[char-misc] mei: me: reduce the scope on unexpected reset

[char-misc] mei: me: reduce the scope on unexpected reset

[Alexander Usyskin]

Avoid false-positive detection of unready hardware by
triggering link reset only when we have driver in ENABLED state.

Cc: stable@vger.kernel.org
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221023
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Fixes: 2cedb296988c ("mei: me: trigger link reset if hw ready is unexpected")
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
 drivers/misc/mei/hw-me.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index d4612c659784..1e4a41ac428f 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1337,19 +1337,13 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
 	/*  check if we need to start the dev */
 	if (!mei_host_is_ready(dev)) {
 		if (mei_hw_is_ready(dev)) {
-			/* synchronized by dev mutex */
-			if (waitqueue_active(&dev->wait_hw_ready)) {
-				dev_dbg(&dev->dev, "we need to start the dev.\n");
-				dev->recvd_hw_ready = true;
-				wake_up(&dev->wait_hw_ready);
-			} else if (dev->dev_state != MEI_DEV_UNINITIALIZED &&
-				   dev->dev_state != MEI_DEV_POWERING_DOWN &&
-				   dev->dev_state != MEI_DEV_POWER_DOWN) {
+			if (dev->dev_state == MEI_DEV_ENABLED) {
 				dev_dbg(&dev->dev, "Force link reset.\n");
 				schedule_work(&dev->reset_work);
 			} else {
-				dev_dbg(&dev->dev, "Ignore this interrupt in state = %d\n",
-					dev->dev_state);
+				dev_dbg(&dev->dev, "we need to start the dev.\n");
+				dev->recvd_hw_ready = true;
+				wake_up(&dev->wait_hw_ready);
 			}
 		} else {
 			dev_dbg(&dev->dev, "Spurious Interrupt\n");
-- 
2.43.0

RE: [char-misc] mei: me: reduce the scope on unexpected reset

[Usyskin, Alexander]

> Subject: [char-misc] mei: me: reduce the scope on unexpected reset
> 
> Avoid false-positive detection of unready hardware by
> triggering link reset only when we have driver in ENABLED state.
> 
> Cc: stable@vger.kernel.org
> Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221023
> Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
> Fixes: 2cedb296988c ("mei: me: trigger link reset if hw ready is unexpected")
> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
> ---
>  drivers/misc/mei/hw-me.c | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 

Hi Greg, is something wrong with this patch?
Am I doing something wrong in To and Cc?
It fixes pretty serious regression, and I prefer to have it merged in this cycle...

- - 
Thanks,
Sasha