From: Sven Van Asbroeck thesven73@gmail.com
[ Upstream commit 2b52a4b65bc8f14520fe6e996ea7fb3f7e400761 ]
In the net core, the struct net_device_ops -> ndo_set_rx_mode() callback is called with the dev->addr_list_lock spinlock held.
However, this driver's ndo_set_rx_mode callback eventually calls lan743x_dp_write(), which acquires a mutex. Mutex acquisition may sleep, and this is not allowed when holding a spinlock.
Fix by removing the dp_lock mutex entirely. Its purpose is to prevent concurrent accesses to the data port. No concurrent accesses are possible, because the dev->addr_list_lock spinlock in the core only lets through one thread at a time.
Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver") Signed-off-by: Sven Van Asbroeck thesven73@gmail.com Link: https://lore.kernel.org/r/20201109203828.5115-1-TheSven73@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/microchip/lan743x_main.c | 12 +++--------- drivers/net/ethernet/microchip/lan743x_main.h | 3 --- 2 files changed, 3 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index 208341541087..085fdceb3821 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -672,14 +672,12 @@ static int lan743x_intr_open(struct lan743x_adapter *adapter) static int lan743x_dp_write(struct lan743x_adapter *adapter, u32 select, u32 addr, u32 length, u32 *buf) { - int ret = -EIO; u32 dp_sel; int i;
- mutex_lock(&adapter->dp_lock); if (lan743x_csr_wait_for_bit(adapter, DP_SEL, DP_SEL_DPRDY_, 1, 40, 100, 100)) - goto unlock; + return -EIO; dp_sel = lan743x_csr_read(adapter, DP_SEL); dp_sel &= ~DP_SEL_MASK_; dp_sel |= select; @@ -691,13 +689,10 @@ static int lan743x_dp_write(struct lan743x_adapter *adapter, lan743x_csr_write(adapter, DP_CMD, DP_CMD_WRITE_); if (lan743x_csr_wait_for_bit(adapter, DP_SEL, DP_SEL_DPRDY_, 1, 40, 100, 100)) - goto unlock; + return -EIO; } - ret = 0;
-unlock: - mutex_unlock(&adapter->dp_lock); - return ret; + return 0; }
static u32 lan743x_mac_mii_access(u16 id, u16 index, int read) @@ -2679,7 +2674,6 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
adapter->intr.irq = adapter->pdev->irq; lan743x_csr_write(adapter, INT_EN_CLR, 0xFFFFFFFF); - mutex_init(&adapter->dp_lock);
ret = lan743x_gpio_init(adapter); if (ret) diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h index 2d6eea18973e..77273be2d1ee 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.h +++ b/drivers/net/ethernet/microchip/lan743x_main.h @@ -702,9 +702,6 @@ struct lan743x_adapter { struct lan743x_csr csr; struct lan743x_intr intr;
- /* lock, used to prevent concurrent access to data port */ - struct mutex dp_lock; - struct lan743x_gpio gpio; struct lan743x_ptp ptp;