This is a note to let you know that I've just added the patch titled mailbox: imx: Fix Tx doorbell shutdown path to the 5.4-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: mailbox-imx-fix-tx-doorbell-shutdown-path.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 985c8e0fff2c9324e7223fd483d2304b61b934ba Author: Daniel Baluta <daniel.baluta@xxxxxxx> Date: Wed Oct 9 16:07:18 2019 +0800 mailbox: imx: Fix Tx doorbell shutdown path [ 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@xxxxxxxxxxxxxx> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx> Signed-off-by: Jassi Brar <jaswinder.singh@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c index d28bbd47ff88..afe625e88a5c 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; + } switch (cp->type) { case IMX_MU_TYPE_TX: