This is a note to let you know that I've just added the patch titled
bus: ti-sysc: Flush posted write on enable before reset
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bus-ti-sysc-flush-posted-write-on-enable-before-reset.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 34539b442b3bc7d5bf10164750302b60b91f18a7 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Wed, 14 Jun 2023 10:18:23 +0300
Subject: bus: ti-sysc: Flush posted write on enable before reset
From: Tony Lindgren <tony@xxxxxxxxxxx>
commit 34539b442b3bc7d5bf10164750302b60b91f18a7 upstream.
The am335x devices started producing boot errors for resetting musb module
in because of subtle timing changes:
Unhandled fault: external abort on non-linefetch (0x1008)
...
sysc_poll_reset_sysconfig from sysc_reset+0x109/0x12
sysc_reset from sysc_probe+0xa99/0xeb0
...
The fix is to flush posted write after enable before reset during
probe. Note that some devices also need to specify the delay after enable
with ti,sysc-delay-us, but this is not needed for musb on am335x based on
my tests.
Reported-by: kernelci.org bot <bot@xxxxxxxxxxxx>
Closes: https://storage.kernelci.org/next/master/next-20230614/arm/multi_v7_defconfig+CONFIG_THUMB2_KERNEL=y/gcc-10/lab-cip/baseline-beaglebone-black.html
Fixes: 596e7955692b ("bus: ti-sysc: Add support for software reset")
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -978,6 +978,8 @@ static int sysc_reset(struct sysc *ddata
val = sysc_read(ddata, offset);
val |= (0x1 << ddata->cap->regbits->srst_shift);
sysc_write(ddata, offset, val);
+ /* Flush posted write */
+ val = sysc_read_sysconfig(ddata);
/* Poll on reset status */
offset = ddata->offsets[SYSC_SYSSTATUS];
Patches currently in stable-queue which might be from tony@xxxxxxxxxxx are
queue-4.19/bus-ti-sysc-flush-posted-write-on-enable-before-reset.patch
queue-4.19/serial-8250-fix-oops-for-port-pm-on-uart_change_pm.patch
