From b925c9de46870853476456140cf2314c7fbcb667 Mon Sep 17 00:00:00 2001 From: Roman Bacik Date: Thu, 24 Aug 2023 14:23:51 -0700 Subject: [PATCH] i2c: iproc: handle invalid slave state [ 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 Fixes: 1ca1b4516088 ("i2c: iproc: handle Master aborted error") Acked-by: Ray Jui Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-bcm-iproc.c | 167 ++++++++++++++++------------- 1 file changed, 92 insertions(+), 75 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; + } + } + } - 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"); + /* 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; + } + + 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) @@ -420,6 +438,64 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, u32 val; u8 value; + + if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { + iproc_i2c->tx_underrun++; + if (iproc_i2c->tx_underrun == 1) + /* Start of SMBUS for Master Read */ + i2c_slave_event(iproc_i2c->slave, + I2C_SLAVE_READ_REQUESTED, + &value); + else + /* Master read other than start */ + i2c_slave_event(iproc_i2c->slave, + I2C_SLAVE_READ_PROCESSED, + &value); + + iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); + /* start transfer */ + val = BIT(S_CMD_START_BUSY_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); + + /* clear interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, + BIT(IS_S_TX_UNDERRUN_SHIFT)); + } + + /* Stop received from master in case of master read transaction */ + if (status & BIT(IS_S_START_BUSY_SHIFT)) { + /* + * Disable interrupt for TX FIFO becomes empty and + * less than PKT_LENGTH bytes were output on the SMBUS + */ + iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); + 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); + iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val); + + val = BIT(S_CMD_START_BUSY_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); + + /* flush TX FIFOs */ + val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET); + val |= (BIT(S_FIFO_TX_FLUSH_SHIFT)); + iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); + + i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); + + /* clear interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, + BIT(IS_S_START_BUSY_SHIFT)); + } + + /* 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 @@ -453,72 +529,13 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, /* 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); + /* 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); + } } - if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { - iproc_i2c->tx_underrun++; - if (iproc_i2c->tx_underrun == 1) - /* Start of SMBUS for Master Read */ - i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_READ_REQUESTED, - &value); - else - /* Master read other than start */ - i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_READ_PROCESSED, - &value); - - iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); - /* start transfer */ - val = BIT(S_CMD_START_BUSY_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); - - /* clear interrupt */ - iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, - BIT(IS_S_TX_UNDERRUN_SHIFT)); - } - - /* Stop received from master in case of master read transaction */ - if (status & BIT(IS_S_START_BUSY_SHIFT)) { - /* - * Disable interrupt for TX FIFO becomes empty and - * 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); - - /* End of SMBUS for Master Read */ - val = BIT(S_TX_WR_STATUS_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val); - - val = BIT(S_CMD_START_BUSY_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); - - /* flush TX FIFOs */ - val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET); - val |= (BIT(S_FIFO_TX_FLUSH_SHIFT)); - iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); - - i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); - - /* clear interrupt */ - iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, - 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); - return true; }