From: Marek Vasut marex@denx.de
[ Upstream commit 743e227a895923c37a333eb2ebf3e391f00c406d ]
The __xiic_start_xfer() manipulates the interrupt flags, xiic_wakeup() may result in return from xiic_xfer() early. Defer both to the end of the xiic_process() interrupt thread, so that they are executed after all the other interrupt bits handling completed and once it completely safe to perform changes to the interrupt bits in the hardware.
Signed-off-by: Marek Vasut marex@denx.de Acked-by: Michal Simek michal.simek@xilinx.com Signed-off-by: Wolfram Sang wsa@kernel.org Stable-dep-of: cb6e45c9a0ad ("i2c: xiic: Don't try to handle more interrupt events after error") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-xiic.c | 37 ++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index 34b8da949462a..14926b193e0ee 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -375,6 +375,9 @@ static irqreturn_t xiic_process(int irq, void *dev_id) struct xiic_i2c *i2c = dev_id; u32 pend, isr, ier; u32 clr = 0; + int xfer_more = 0; + int wakeup_req = 0; + int wakeup_code = 0;
/* Get the interrupt Status from the IPIF. There is no clearing of * interrupts in the IPIF. Interrupts must be cleared at the source. @@ -411,10 +414,14 @@ static irqreturn_t xiic_process(int irq, void *dev_id) */ xiic_reinit(i2c);
- if (i2c->rx_msg) - xiic_wakeup(i2c, STATE_ERROR); - if (i2c->tx_msg) - xiic_wakeup(i2c, STATE_ERROR); + if (i2c->rx_msg) { + wakeup_req = 1; + wakeup_code = STATE_ERROR; + } + if (i2c->tx_msg) { + wakeup_req = 1; + wakeup_code = STATE_ERROR; + } } if (pend & XIIC_INTR_RX_FULL_MASK) { /* Receive register/FIFO is full */ @@ -448,8 +455,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id) i2c->tx_msg++; dev_dbg(i2c->adap.dev.parent, "%s will start next...\n", __func__); - - __xiic_start_xfer(i2c); + xfer_more = 1; } } } @@ -463,11 +469,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id) if (!i2c->tx_msg) goto out;
- if ((i2c->nmsgs == 1) && !i2c->rx_msg && - xiic_tx_space(i2c) == 0) - xiic_wakeup(i2c, STATE_DONE); + wakeup_req = 1; + + if (i2c->nmsgs == 1 && !i2c->rx_msg && + xiic_tx_space(i2c) == 0) + wakeup_code = STATE_DONE; else - xiic_wakeup(i2c, STATE_ERROR); + wakeup_code = STATE_ERROR; } if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { /* Transmit register/FIFO is empty or ½ empty */ @@ -491,7 +499,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id) if (i2c->nmsgs > 1) { i2c->nmsgs--; i2c->tx_msg++; - __xiic_start_xfer(i2c); + xfer_more = 1; } else { xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
@@ -509,6 +517,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id) dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr); + if (xfer_more) + __xiic_start_xfer(i2c); + if (wakeup_req) + xiic_wakeup(i2c, wakeup_code); + + WARN_ON(xfer_more && wakeup_req); + mutex_unlock(&i2c->lock); return IRQ_HANDLED; }