The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel num fail") Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com --- .../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle *handle, static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) { - int ret; + const struct hnae3_ae_ops *ops = handle->ae_algo->ops; + u32 org_tqp_num = handle->kinfo.num_tqps; + struct device *dev = &handle->pdev->dev; + u32 req_tqp_num = new_tqp_num; + bool revert_old_config = false; + int ret, retval = 0; + + /* bring down the client */ + ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT); + if (ret) { + dev_err(dev, "client down fail, this should'nt have happened!\n"); + return ret; + }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num, - rxfh_configured); + ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) { - dev_err(&handle->pdev->dev, - "Change tqp num(%u) fail.\n", new_tqp_num); + dev_err(dev, "client uninit fail, this should'nt have happened!\n"); return ret; }
+revert_old_tpqs_config: + /* update the TX Sched and RSS config in the H/W */ + ret = ops->set_channels(handle, req_tqp_num, rxfh_configured); + if (ret) { + dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n", + ret, revert_old_config ? "old" : "new"); + goto err_set_channel; + } + + /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT); - if (ret) - return ret; + if (ret) { + dev_err(dev, "failed to initialize the client again\n"); + goto err_set_channel; + }
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT); - if (ret) - hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); + if (ret) { + dev_err(dev, "Client up fail, this should'nt have happened!\n"); + return ret; + } + + return retval; +err_set_channel: + if (!revert_old_config) { + dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n"); + req_tqp_num = org_tqp_num; + revert_old_config = true; + retval = ret; + goto revert_old_tpqs_config; + }
+ dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n"); + dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret; }
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count; - u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev)) @@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT); - if (ret) - return ret; - - ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT); - if (ret) - return ret; - - org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) { - int ret1; - - netdev_warn(netdev, - "Change channels fail, revert to old value\n"); - ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured); - if (ret1) { - netdev_err(netdev, - "revert to old channel fail\n"); - return ret1; - } - + netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret, + new_tqp_num); return ret; }
在 2021/4/24 22:51, Salil Mehta 写道:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
I do not really get the problem here, what is not proper.
before/therafter --- is any mistake here?
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel num fail") Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle *handle, static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) {
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
dev_err(dev, "Client up fail, this should'nt have happened!\n");return ret;- }
- return retval;
+err_set_channel:
if (!revert_old_config) {
dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n");req_tqp_num = org_tqp_num;revert_old_config = true;retval = ret;goto revert_old_tpqs_config;}
dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n");
dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret; }
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count;
u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev))
@@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT);
- if (ret)
return ret;- ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT);
- if (ret)
return ret;- org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) {
int ret1;netdev_warn(netdev,"Change channels fail, revert to old value\n");ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured);if (ret1) {netdev_err(netdev,"revert to old channel fail\n");return ret1;}
netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret,new_tqp_num);
From: lipeng (Y) Sent: Sunday, April 25, 2021 2:46 AM
在 2021/4/24 22:51, Salil Mehta 写道:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
I do not really get the problem here, what is not proper.
I should admit that I had loosely put the subject and the matter in earlier RFC patch I shared and I copied it here the same. I need to update the subject and also perhaps re-word it to clarify what is it is precisely doing before finally sending it. Perhaps I will be breaking this patch into further smaller changes and sending it to 'net-next' instead of 'net' repo.
For now, I have explained the problems and inconsistencies in their handling below.
before/therafter --- is any mistake here?
Above is what you call 'change' and the code in the patch reflects it.
Multiple problems: 1. Logic used during recovery is inconsistent. For example, below are the handling cases from the existing/previous code:
Case 1: int hns3_set_channels(struct net_device *netdev, struct ethtool_channels *ch) { [...]
ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT); if (ret) return ret;
ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT); if (ret) return ret;
Problem 1: Here above, we don’t care to handle the error properly or even print the message to the user what caused an error. In this case, user will find the net_device in *down* state after failure to configure the specified number of channels.
Resolution: If we cannot do much with the returned error we should at least intimate Or instruct user what to do to get out of the state.
Problem 2: If we have intentionally fabricated hns3_reset_notify() API to necessarily return errors for all types maybe because we think operations like HNAE3_UNINIT_CLIENT can return error then we cannot assume after this error device will be in sane state.
Resolution: This then again requires user to be intimated about this and user can either reload the driver or reset.
Problem 3: the return types of hns3_reset_notify() for the HNAE3_{DOWN, UINIT}_CLIENT are not . Ideally they should be *void* since netif_tx_stop_all_queues() and netif_carrier_off() are void.
Resolution: If we need to solve this then we require separate patch and should follow this patch. Ideally, none of the operations HNAE3_{DOWN, UINIT}_CLIENT should return error.
Problem 4: Client down and restore logic is spanning across functions i.e. It is brought *down* within hns3_set_channels() and then is restored inside function hns3_change_channels() but then half of the error handling is being done inside the hns3_change_channels() and then other half of restoring to the old TPQ is being initiated from hns3_set_channels(). All of these are against the principles of good "structured programming".
The functions naming and prototype should be such that one does not have to read the entire code inside always. It should do to the entirety (along with any fallbacks/reverts inside) what its name suggest i.e. almost self-contained - all related code inside it!
"Structured Programming" is a paradigm just like "Object-Oriented Programming"
Resolution: Either entire logic including the error handling/fallback should exist within the hns3_set_channels() OR we should make the function hns3_change_channels() self-contained. This patch does later.
[...] }
Case 2: static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) { int ret;
ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num, rxfh_configured); if (ret) { dev_err(&handle->pdev->dev, "Change tqp num(%u) fail.\n", new_tqp_num); return ret; }
Problem 5: If this happens multiple times then earlier code just returns with some error to the user not indicating that this device now is not in a functional state. Hence, user will need to reset or reload the driver.
Handling in hns3_set_channels(): if (ret1) { netdev_err(netdev, "revert to old channel fail\n"); return ret1;
After above, user will find that net device is either missing or not functional.
Resolution: Indicate to the user clearly what went wrong and how to come out of it. This is part and parcel of the handling of errors and fallback logic. This patch does that.
Problem 6: After HNAE3_UP_CLIENT fails(which ideally should never) the error handling is to reverse the earlier successful initialization of the client. Why?
If this happens
ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT); if (ret) return ret;
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT); if (ret) hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
return ret; }
1. If above operation also fails why should handling be different than when "ifconfig <netdev> up" fails(if ever)? 2. Could we not just ask user to attempt to UP the net_device manually? OR 3. Request user to reset the device or reload the driver if he faces further failure?
Resolution: Just intimate user with appropriate error and advice to reset or reload the driver if further error persists. This is the approach being taken in the patch.
Thanks Salil.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel
num fail")
Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle
*handle,
static int hns3_change_channels(struct hnae3_handle *handle, u32
new_tqp_num,
bool rxfh_configured){
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
dev_err(dev, "Client up fail, this should'nt have happened!\n");return ret;- }
- return retval;
+err_set_channel:
if (!revert_old_config) {
dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n");req_tqp_num = org_tqp_num;revert_old_config = true;retval = ret;goto revert_old_tpqs_config;}
dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n");
dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret; }
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count;
u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev))
@@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT);
- if (ret)
return ret;- ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT);
- if (ret)
return ret;- org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) {
int ret1;netdev_warn(netdev,"Change channels fail, revert to old value\n");ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured);if (ret1) {netdev_err(netdev,"revert to old channel fail\n");return ret1;}
netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret,new_tqp_num);
在 2021/4/24 22:51, Salil Mehta 写道:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel num fail") Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle *handle, static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) {
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
dev_err(dev, "Client up fail, this should'nt have happened!\n");return ret;- }
- return retval;
+err_set_channel:
- if (!revert_old_config) {
dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n");req_tqp_num = org_tqp_num;revert_old_config = true;retval = ret;goto revert_old_tpqs_config;
Hi,salil,
Huawei C programming specification requires goto statement cannot jump up.
}
dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n");
dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret; }
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count;
u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev))
@@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT);
- if (ret)
return ret;- ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT);
- if (ret)
return ret;- org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) {
int ret1;netdev_warn(netdev,"Change channels fail, revert to old value\n");ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured);if (ret1) {netdev_err(netdev,"revert to old channel fail\n");return ret1;}
netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret,new_tqp_num);
From: lipeng (Y) Sent: Friday, June 25, 2021 2:03 AM
在 2021/4/24 22:51, Salil Mehta 写道:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel num fail") Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle *handle, static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) {
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
dev_err(dev, "Client up fail, this should'nt have happened!\n");return ret;- }
- return retval;
+err_set_channel:
- if (!revert_old_config) {
dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n");req_tqp_num = org_tqp_num;revert_old_config = true;retval = ret;goto revert_old_tpqs_config;Hi,salil,
Huawei C programming specification requires goto statement cannot jump up.
Hi Lipeng,
New code is: 1. Making existing code *more structured* by correcting the overspill of the change channel logic beyond function hns3_change_channels(). Right now, its half inside and half outside. 2. Ensuring the gotos are within the same scope of the function and it is bounded jump. 3. Goto is part of the exception leg of the code rather the normal code. In our case it only happens once in case when failure occurs and we need to attempt to restore older config. This is clearly an exception leg and not random jumps. 4. Fixing existing problems with the code. 5. Lastly, use of the goto is also within the visible boundary of the function.
With respect to the section in you guidelines: Link: http://openx.huawei.com/communityWikiDetails?communityId=41&ibid=SPE1000...
There is difference in what example function listed in above link is trying to do with gotos and what the goto in this patch is doing. 1. Above function is using goto to jump out of the loop in normal execution flow. Goto in the patch is being used only in the exceptional condition i.e. when normal flow encounters a failure in some leg. 2. goto statement in above example looks unbounded. Goto statement in the .patch is bounded and in fact executed only once even in exceptional circumstance of restoring older config. 3. Goto in above example looks avoidable but goto in the patch being submitted is the last resort we are using as a tradeoff to braking the structured paradigm. Later is more important.
In simple terms, goto which generally is termed as the one which breaks structured programming, here it is helping to restore structured programing by very limited and controlled use of just *one* jump in the exceptional failure case. It is ironical but I think it is a perfectly fine tradeoff.
Thanks
}
dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n");
dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret; }
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count;
u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev))
@@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT);
- if (ret)
return ret;- ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT);
- if (ret)
return ret;- org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) {
int ret1;netdev_warn(netdev,"Change channels fail, revert to old value\n");ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured);if (ret1) {netdev_err(netdev,"revert to old channel fail\n");return ret1;}
netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret,new_tqp_num);
On 2021/4/24 22:51, Salil Mehta wrote:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel num fail") Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle *handle, static int hns3_change_channels(struct hnae3_handle *handle, u32 new_tqp_num, bool rxfh_configured) {
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
Inverted triangle structure required
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
If exits directly without uninit here, init will be executed repeatedly, causing memory leakage issue.
dev_err(dev, "Client up fail, this should'nt have happened!\n");return ret;- }
- return retval;
+err_set_channel:
if (!revert_old_config) {
dev_warn(dev, "Revert TX Sched/RSS H/W config with old TPQs\n");req_tqp_num = org_tqp_num;revert_old_config = true;retval = ret;goto revert_old_tpqs_config;}
dev_err(dev, "Bad, we could'nt revert to old TPQ H/W config\n");
dev_warn(dev, "Device maybe insane. Reload driver/Reset required!\n"); return ret;
}
@@ -4720,7 +4756,6 @@ int hns3_set_channels(struct net_device *netdev, struct hnae3_knic_private_info *kinfo = &h->kinfo; bool rxfh_configured = netif_is_rxfh_configured(netdev); u32 new_tqp_num = ch->combined_count;
u16 org_tqp_num; int ret;
if (hns3_nic_resetting(netdev))
@@ -4750,28 +4785,10 @@ int hns3_set_channels(struct net_device *netdev, "set channels: tqp_num=%u, rxfh=%d\n", new_tqp_num, rxfh_configured);
- ret = hns3_reset_notify(h, HNAE3_DOWN_CLIENT);
- if (ret)
return ret;- ret = hns3_reset_notify(h, HNAE3_UNINIT_CLIENT);
- if (ret)
return ret;- org_tqp_num = h->kinfo.num_tqps; ret = hns3_change_channels(h, new_tqp_num, rxfh_configured); if (ret) {
int ret1;netdev_warn(netdev,"Change channels fail, revert to old value\n");ret1 = hns3_change_channels(h, org_tqp_num, rxfh_configured);if (ret1) {netdev_err(netdev,"revert to old channel fail\n");return ret1;}
netdev_err(netdev, "fail(=%d) to set number of channels to %u\n", ret,new_tqp_num);
From: moyufeng Sent: Friday, June 25, 2021 3:13 AM
On 2021/4/24 22:51, Salil Mehta wrote:
The fallback logic of the set channels when set_channel() fails to configure TX Sched/RSS H/W configuration or for the code which brings down/restores client before/therafter is not handled properly.
Fix and refactor the code for handling the errors properly and to improve the readibility.
Fixes: 3a5a5f06d4d2 ("net: hns3: revert to old channel when setting new channel
num fail")
Signed-off-by: Salil Mehta salil.mehta@huawei.com Signed-off-by: Peng Li lipeng321@huawei.com
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 77 +++++++++++-------- 1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index bf4302a5cf95..fbb0f4c9b98e 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4692,24 +4692,60 @@ static int hns3_reset_notify(struct hnae3_handle
*handle,
static int hns3_change_channels(struct hnae3_handle *handle, u32
new_tqp_num,
bool rxfh_configured){
- int ret;
- const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
- u32 org_tqp_num = handle->kinfo.num_tqps;
- struct device *dev = &handle->pdev->dev;
- u32 req_tqp_num = new_tqp_num;
- bool revert_old_config = false;
Inverted triangle structure required
yes, we can do that.
- int ret, retval = 0;
- /* bring down the client */
- ret = hns3_reset_notify(handle, HNAE3_DOWN_CLIENT);
- if (ret) {
dev_err(dev, "client down fail, this should'nt have happened!\n");return ret;- }
- ret = handle->ae_algo->ops->set_channels(handle, new_tqp_num,
rxfh_configured);
- ret = hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT); if (ret) {
dev_err(&handle->pdev->dev,"Change tqp num(%u) fail.\n", new_tqp_num);
dev_err(dev, "client uninit fail, this should'nt have happened!\n");+revert_old_tpqs_config:
- /* update the TX Sched and RSS config in the H/W */
- ret = ops->set_channels(handle, req_tqp_num, rxfh_configured);
- if (ret) {
dev_err(dev, "TX Sched/RSS H/W cfg fail(=%d) for %s TPQs\n",ret, revert_old_config ? "old" : "new");goto err_set_channel;- }
- /* restore the client */ ret = hns3_reset_notify(handle, HNAE3_INIT_CLIENT);
- if (ret)
return ret;
if (ret) {
dev_err(dev, "failed to initialize the client again\n");goto err_set_channel;}
ret = hns3_reset_notify(handle, HNAE3_UP_CLIENT);
- if (ret)
hns3_reset_notify(handle, HNAE3_UNINIT_CLIENT);
- if (ret) {
If exits directly without uninit here, init will be executed repeatedly, causing memory leakage issue.
No. this is not the case as explained and *agreed* in the espace.
In crux, failure of bringing UP a device does not need to uninit the client again. It does not makes sense as reset was a success.
User can use manual "ifconfig <netdev> up" command to bring it up. It that does not works it’s a bug in the firmware as UP can only fail if queue reset fails.
This case is no different than when device is left when DOWN. It is perfectly in sane state unless firmware has a bug. Ideally, bug should never fail!
Thanks
-
lipeng (Y) -
moyufeng -
Salil Mehta