From e7b87de822f42110ae8419f2c178d951cd94d39e Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: Apr 20 2023 11:01:08 +0000
Subject: i2c: ocores: generate stop condition after timeout in polling

mode (bsc#1012628).

---

diff --git a/patches.kernel.org/6.2.12-132-i2c-ocores-generate-stop-condition-after-timeo.patch b/patches.kernel.org/6.2.12-132-i2c-ocores-generate-stop-condition-after-timeo.patch
new file mode 100644
index 0000000..bd55f46
--- /dev/null
+++ b/patches.kernel.org/6.2.12-132-i2c-ocores-generate-stop-condition-after-timeo.patch
@@ -0,0 +1,108 @@
+From: Gregor Herburger <gregor.herburger@tq-group.com>
+Date: Thu, 13 Apr 2023 11:37:37 +0200
+Subject: [PATCH] i2c: ocores: generate stop condition after timeout in polling
+ mode
+References: bsc#1012628
+Patch-mainline: 6.2.12
+Git-commit: f8160d3b35fc94491bb0cb974dbda310ef96c0e2
+
+[ Upstream commit f8160d3b35fc94491bb0cb974dbda310ef96c0e2 ]
+
+In polling mode, no stop condition is generated after a timeout. This
+causes SCL to remain low and thereby block the bus. If this happens
+during a transfer it can cause slaves to misinterpret the subsequent
+transfer and return wrong values.
+
+To solve this, pass the ETIMEDOUT error up from ocores_process_polling()
+instead of setting STATE_ERROR directly. The caller is adjusted to call
+ocores_process_timeout() on error both in polling and in IRQ mode, which
+will set STATE_ERROR and generate a stop condition.
+
+Fixes: 69c8c0c0efa8 ("i2c: ocores: add polling interface")
+Signed-off-by: Gregor Herburger <gregor.herburger@tq-group.com>
+Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
+Acked-by: Peter Korsgaard <peter@korsgaard.com>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Reviewed-by: Federico Vaga <federico.vaga@cern.ch>
+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-ocores.c | 35 ++++++++++++++++++---------------
+ 1 file changed, 19 insertions(+), 16 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
+index a0af027d..2e575856 100644
+--- a/drivers/i2c/busses/i2c-ocores.c
++++ b/drivers/i2c/busses/i2c-ocores.c
+@@ -342,18 +342,18 @@ static int ocores_poll_wait(struct ocores_i2c *i2c)
+  * ocores_isr(), we just add our polling code around it.
+  *
+  * It can run in atomic context
++ *
++ * Return: 0 on success, -ETIMEDOUT on timeout
+  */
+-static void ocores_process_polling(struct ocores_i2c *i2c)
++static int ocores_process_polling(struct ocores_i2c *i2c)
+ {
+-	while (1) {
+-		irqreturn_t ret;
+-		int err;
++	irqreturn_t ret;
++	int err = 0;
+ 
++	while (1) {
+ 		err = ocores_poll_wait(i2c);
+-		if (err) {
+-			i2c->state = STATE_ERROR;
++		if (err)
+ 			break; /* timeout */
+-		}
+ 
+ 		ret = ocores_isr(-1, i2c);
+ 		if (ret == IRQ_NONE)
+@@ -364,13 +364,15 @@ static void ocores_process_polling(struct ocores_i2c *i2c)
+ 					break;
+ 		}
+ 	}
++
++	return err;
+ }
+ 
+ static int ocores_xfer_core(struct ocores_i2c *i2c,
+ 			    struct i2c_msg *msgs, int num,
+ 			    bool polling)
+ {
+-	int ret;
++	int ret = 0;
+ 	u8 ctrl;
+ 
+ 	ctrl = oc_getreg(i2c, OCI2C_CONTROL);
+@@ -388,15 +390,16 @@ static int ocores_xfer_core(struct ocores_i2c *i2c,
+ 	oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
+ 
+ 	if (polling) {
+-		ocores_process_polling(i2c);
++		ret = ocores_process_polling(i2c);
+ 	} else {
+-		ret = wait_event_timeout(i2c->wait,
+-					 (i2c->state == STATE_ERROR) ||
+-					 (i2c->state == STATE_DONE), HZ);
+-		if (ret == 0) {
+-			ocores_process_timeout(i2c);
+-			return -ETIMEDOUT;
+-		}
++		if (wait_event_timeout(i2c->wait,
++				       (i2c->state == STATE_ERROR) ||
++				       (i2c->state == STATE_DONE), HZ) == 0)
++			ret = -ETIMEDOUT;
++	}
++	if (ret) {
++		ocores_process_timeout(i2c);
++		return ret;
+ 	}
+ 
+ 	return (i2c->state == STATE_DONE) ? num : -EIO;
+-- 
+2.35.3
+
diff --git a/series.conf b/series.conf
index 28bbc59..dd1b368 100644
--- a/series.conf
+++ b/series.conf
@@ -2359,6 +2359,7 @@
 	patches.kernel.org/6.2.12-129-powerpc-papr_scm-Update-the-NUMA-distance-tabl.patch
 	patches.kernel.org/6.2.12-130-sched-fair-Fix-imbalance-overflow.patch
 	patches.kernel.org/6.2.12-131-x86-rtc-Remove-__init-for-runtime-functions.patch
+	patches.kernel.org/6.2.12-132-i2c-ocores-generate-stop-condition-after-timeo.patch
 
 	########################################################
 	# Build fixes that apply to the vanilla kernel too.