From: Yicong Yang <yangyicong@hisilicon.com>
Date: Mon, 13 Mar 2023 15:45:52 +0800
Subject: [PATCH] i2c: hisi: Only use the completion interrupt to finish the
 transfer
References: bsc#1012628
Patch-mainline: 6.2.9
Git-commit: d98263512684a47e81bcb72a5408958ecd1e60b0

[ Upstream commit d98263512684a47e81bcb72a5408958ecd1e60b0 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/i2c/busses/i2c-hisi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c
index 8c6c7075..f5c37d2f 100644
--- a/drivers/i2c/busses/i2c-hisi.c
+++ b/drivers/i2c/busses/i2c-hisi.c
@@ -341,7 +341,11 @@ 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);
-- 
2.35.3