i2c: hisi: Only use the completion interrupt to finish the transfer

The controller will always generate a completion interrupt when the
transfer is finished normally or not. Currently we use either error or
completion interrupt to finish, this may result the completion
interrupt unhandled and corrupt the next transfer, especially at low
speed mode. Since on error case, the error interrupt will come first
then is the completion interrupt. So only use the completion interrupt
to finish the whole transfer process.

Fixes: d62fbdb99a85 ("i2c: add support for HiSilicon I2C controller")
Reported-by: Sheng Feng <fengsheng5@huawei.com>
Signed-off-by: Sheng Feng <fengsheng5@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c
index 1b7609a34f4a737684aa3198575cd8edaa30605a..e067671b3ce2eebed4eab2cb51301aaaa3890529 100644 (file)
--- a/drivers/i2c/busses/i2c-hisi.c
+++ b/drivers/i2c/busses/i2c-hisi.c
@@ -348,7 +348,11 @@ static irqreturn_t hisi_i2c_irq(int irq, void *context)
                hisi_i2c_read_rx_fifo(ctlr);
 
 out:
-       if (int_stat & HISI_I2C_INT_TRANS_CPLT || ctlr->xfer_err) {
+       /*
+        * Only use TRANS_CPLT to indicate the completion. On error cases we'll
+        * get two interrupts, INT_ERR first then TRANS_CPLT.
+        */
+       if (int_stat & HISI_I2C_INT_TRANS_CPLT) {
                hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
                hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
                complete(ctlr->completion);