[PATCH OLK-6.6 572/602] i2c: iproc: handle invalid slave state

From: Roman Bacik roman.bacik@broadcom.com

stable inclusion from stable-v6.6.2 commit b925c9de46870853476456140cf2314c7fbcb667 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8IW7G

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit ba15a14399c262f91ce30c19fcbdc952262dd1be ]

Add the code to handle an invalid state when both bits S_RX_EVENT (indicating a transaction) and S_START_BUSY (indicating the end of transaction - transition of START_BUSY from 1 to 0) are set in the interrupt status register during a slave read.

Signed-off-by: Roman Bacik roman.bacik@broadcom.com Fixes: 1ca1b4516088 ("i2c: iproc: handle Master aborted error") Acked-by: Ray Jui ray.jui@broadcom.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/i2c/busses/i2c-bcm-iproc.c | 133 ++++++++++++++++------------- 1 file changed, 75 insertions(+), 58 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 51aab662050b..e905734c26a0 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -316,26 +316,44 @@ static void bcm_iproc_i2c_slave_init( iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); }

-static void bcm_iproc_i2c_check_slave_status( - struct bcm_iproc_i2c_dev *iproc_i2c) +static bool bcm_iproc_i2c_check_slave_status + (struct bcm_iproc_i2c_dev *iproc_i2c, u32 status) { u32 val; + bool recover = false;

- val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET); - /* status is valid only when START_BUSY is cleared after it was set */ - if (val & BIT(S_CMD_START_BUSY_SHIFT)) - return; + /* check slave transmit status only if slave is transmitting */ + if (!iproc_i2c->slave_rx_only) { + val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET); + /* status is valid only when START_BUSY is cleared */ + if (!(val & BIT(S_CMD_START_BUSY_SHIFT))) { + val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK; + if (val == S_CMD_STATUS_TIMEOUT || + val == S_CMD_STATUS_MASTER_ABORT) { + dev_warn(iproc_i2c->device, + (val == S_CMD_STATUS_TIMEOUT) ? + "slave random stretch time timeout\n" : + "Master aborted read transaction\n"); + recover = true; + } + } + } + + /* RX_EVENT is not valid when START_BUSY is set */ + if ((status & BIT(IS_S_RX_EVENT_SHIFT)) && + (status & BIT(IS_S_START_BUSY_SHIFT))) { + dev_warn(iproc_i2c->device, "Slave aborted read transaction\n"); + recover = true; + }

- val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK; - if (val == S_CMD_STATUS_TIMEOUT || val == S_CMD_STATUS_MASTER_ABORT) { - dev_err(iproc_i2c->device, (val == S_CMD_STATUS_TIMEOUT) ? - "slave random stretch time timeout\n" : - "Master aborted read transaction\n"); + if (recover) { /* re-initialize i2c for recovery */ bcm_iproc_i2c_enable_disable(iproc_i2c, false); bcm_iproc_i2c_slave_init(iproc_i2c, true); bcm_iproc_i2c_enable_disable(iproc_i2c, true); } + + return recover; }

static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c) @@ -420,48 +438,6 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, u32 val; u8 value;

- /* - * Slave events in case of master-write, master-write-read and, - * master-read - * - * Master-write : only IS_S_RX_EVENT_SHIFT event - * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT - * events - * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT - * events or only IS_S_RD_EVENT_SHIFT - * - * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt - * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes - * full. This can happen if Master issues write requests of more than - * 64 bytes. - */ - if (status & BIT(IS_S_RX_EVENT_SHIFT) || - status & BIT(IS_S_RD_EVENT_SHIFT) || - status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { - /* disable slave interrupts */ - val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); - val &= ~iproc_i2c->slave_int_mask; - iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); - - if (status & BIT(IS_S_RD_EVENT_SHIFT)) - /* Master-write-read request */ - iproc_i2c->slave_rx_only = false; - else - /* Master-write request only */ - iproc_i2c->slave_rx_only = true; - - /* schedule tasklet to read data later */ - tasklet_schedule(&iproc_i2c->slave_rx_tasklet); - - /* - * clear only IS_S_RX_EVENT_SHIFT and - * IS_S_RX_FIFO_FULL_SHIFT interrupt. - */ - val = BIT(IS_S_RX_EVENT_SHIFT); - if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) - val |= BIT(IS_S_RX_FIFO_FULL_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val); - }

if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { iproc_i2c->tx_underrun++; @@ -493,8 +469,9 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, * less than PKT_LENGTH bytes were output on the SMBUS */ iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, - iproc_i2c->slave_int_mask); + val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); + val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);

/* End of SMBUS for Master Read */ val = BIT(S_TX_WR_STATUS_SHIFT); @@ -515,9 +492,49 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, BIT(IS_S_START_BUSY_SHIFT)); }

- /* check slave transmit status only if slave is transmitting */ - if (!iproc_i2c->slave_rx_only) - bcm_iproc_i2c_check_slave_status(iproc_i2c); + /* if the controller has been reset, immediately return from the ISR */ + if (bcm_iproc_i2c_check_slave_status(iproc_i2c, status)) + return true; + + /* + * Slave events in case of master-write, master-write-read and, + * master-read + * + * Master-write : only IS_S_RX_EVENT_SHIFT event + * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT + * events + * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT + * events or only IS_S_RD_EVENT_SHIFT + * + * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt + * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes + * full. This can happen if Master issues write requests of more than + * 64 bytes. + */ + if (status & BIT(IS_S_RX_EVENT_SHIFT) || + status & BIT(IS_S_RD_EVENT_SHIFT) || + status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { + /* disable slave interrupts */ + val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); + val &= ~iproc_i2c->slave_int_mask; + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); + + if (status & BIT(IS_S_RD_EVENT_SHIFT)) + /* Master-write-read request */ + iproc_i2c->slave_rx_only = false; + else + /* Master-write request only */ + iproc_i2c->slave_rx_only = true; + + /* schedule tasklet to read data later */ + tasklet_schedule(&iproc_i2c->slave_rx_tasklet); + + /* clear IS_S_RX_FIFO_FULL_SHIFT interrupt */ + if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { + val = BIT(IS_S_RX_FIFO_FULL_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val); + } + }

return true; }