FAILED: patch "[PATCH] i2c: ocores: set IACK bit after core is enabled" failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] i2c: ocores: set IACK bit after core is enabled" failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 5a72477273066b5b357801ab2d315ef14949d402
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024062412-mobster-doable-acc6@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5a72477273066b5b357801ab2d315ef14949d402 Mon Sep 17 00:00:00 2001
From: Grygorii Tertychnyi <grembeter@gmail.com>
Date: Mon, 20 May 2024 17:39:32 +0200
Subject: [PATCH] i2c: ocores: set IACK bit after core is enabled

Setting IACK bit when core is disabled does not clear the "Interrupt Flag"
bit in the status register, and the interrupt remains pending.

Sometimes it causes failure for the very first message transfer, that is
usually a device probe.

Hence, set IACK bit after core is enabled to clear pending interrupt.

Fixes: 18f98b1e3147 ("[PATCH] i2c: New bus driver for the OpenCores I2C controller")
Signed-off-by: Grygorii Tertychnyi <grygorii.tertychnyi@leica-geosystems.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 56a4dabf5a38..4ad670a80a63 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -431,8 +431,8 @@ static int ocores_init(struct device *dev, struct ocores_i2c *i2c)
 	oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
 
 	/* Init the device */
-	oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
 	oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_EN);
+	oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
 
 	return 0;
 }