[PATCH AUTOSEL 4.19 77/79] mailbox: imx: Fix Tx doorbell shutdown path

Sasha Levin
2019-12-11T15:28:34Z

From: Daniel Baluta <daniel.baluta@nxp.com>

[ Upstream commit bf159d151a0b844be28882f39e316b5800acaa2b ]

Tx doorbell is handled by txdb_tasklet and doesn't
have an associated IRQ.

Anyhow, imx_mu_shutdown ignores this and tries to
free an IRQ that wasn't requested for Tx DB resulting
in the following warning:

[ 1.967644] Trying to free already-free IRQ 26
[ 1.972108] WARNING: CPU: 2 PID: 157 at kernel/irq/manage.c:1708 __free_irq+0xc0/0x358
[ 1.980024] Modules linked in:
[ 1.983088] CPU: 2 PID: 157 Comm: kworker/2:1 Tainted: G
[ 1.993524] Hardware name: Freescale i.MX8QXP MEK (DT)
[ 1.998668] Workqueue: events deferred_probe_work_func
[ 2.003812] pstate: 60000085 (nZCv daIf -PAN -UAO)
[ 2.008607] pc : __free_irq+0xc0/0x358
[ 2.012364] lr : __free_irq+0xc0/0x358
[ 2.016111] sp : ffff00001179b7e0
[ 2.019422] x29: ffff00001179b7e0 x28: 0000000000000018
[ 2.024736] x27: ffff000011233000 x26: 0000000000000004
[ 2.030053] x25: 000000000000001a x24: ffff80083bec74d4
[ 2.035369] x23: 0000000000000000 x22: ffff80083bec7588
[ 2.040686] x21: ffff80083b1fe8d8 x20: ffff80083bec7400
[ 2.046003] x19: 0000000000000000 x18: ffffffffffffffff
[ 2.051320] x17: 0000000000000000 x16: 0000000000000000
[ 2.056637] x15: ffff0000111296c8 x14: ffff00009179b517
[ 2.061953] x13: ffff00001179b525 x12: ffff000011142000
[ 2.067270] x11: ffff000011129f20 x10: ffff0000105da970
[ 2.072587] x9 : 00000000ffffffd0 x8 : 0000000000000194
[ 2.077903] x7 : 612065657266206f x6 : ffff0000111e7b09
[ 2.083220] x5 : 0000000000000003 x4 : 0000000000000000
[ 2.088537] x3 : 0000000000000000 x2 : 00000000ffffffff
[ 2.093854] x1 : 28b70f0a2b60a500 x0 : 0000000000000000
[ 2.099173] Call trace:
[ 2.101618] __free_irq+0xc0/0x358
[ 2.105021] free_irq+0x38/0x98
[ 2.108170] imx_mu_shutdown+0x90/0xb0
[ 2.111921] mbox_free_channel.part.2+0x24/0xb8
[ 2.116453] mbox_free_channel+0x18/0x28

This bug is present from the beginning of times.

Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mailbox/imx-mailbox.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 363d35d5e49dc..2f47023cab2b2 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -214,8 +214,10 @@ static void imx_mu_shutdown(struct mbox_chan *chan)
struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
struct imx_mu_con_priv *cp = chan->con_priv;

- if (cp->type == IMX_MU_TYPE_TXDB)
+ if (cp->type == IMX_MU_TYPE_TXDB) {
tasklet_kill(&cp->txdb_tasklet);
+ return;
+ }

imx_mu_xcr_rmw(priv, 0,
IMX_MU_xCR_TIEn(cp->idx) | IMX_MU_xCR_RIEn(cp->idx));
--
2.20.1