Re: [PATCH v1] PCI: pciehp: Fix the slot in BLINKINGON_STATE when Presence Detect Changed event occurred

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Apr 03, 2023 at 01:46:19PM +0800, Rongguang Wei wrote:
> From: Rongguang Wei <weirongguang@kylinos.cn>
> 
> When a Presence Detect Changed event has occurred, the slot status
> in either BLINKINGOFF_STATE or OFF_STATE, turn it off unconditionally.
> But if the slot status is in BLINKINGON_STATE and the slot is currently
> empty, the slot status was staying in BLINKINGON_STATE.
> 
> The message print like this:
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Attention button pressed
>     pcieport 0000:00:01.5: pciehp: Slot(0-5) Powering on due to button press
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Attention button pressed
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Button cancel
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Action canceled due to button press
> 
> It cause the next Attention Button Pressed event become Button cancel
> and missing the Presence Detect Changed event with this button press
> though this button presses event is occurred after 5s.
> 
> According to the Commit d331710ea78f ("PCI: pciehp: Become resilient
> to missed events"), if the slot is currently occupied, turn it on and
> if the slot is empty, it need to set in OFF_STATE rather than stay in
> current status. So the slot which status in BLINKINGON_STATE is also
> turn off unconditionally.
> 
> The message print like this after the patch:
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Attention button pressed
>     pcieport 0000:00:01.5: pciehp: Slot(0-5) Powering on due to button press
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Card not present
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Already disabled
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Attention button pressed
>     pcieport 0000:00:01.5: pciehp: Slot(0-5) Powering on due to button press
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Card not present
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Already disabled
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Card present
>     pcieport 0000:00:01.5: pciehp: Slot(0-5): Link Up
> 
> After that, the next Attention Button Pressed event would power on
> the slot normally.

Lukas, any comment?

> Fixes: d331710ea78f ("PCI: pciehp: Become resilient to missed events")
> Signed-off-by: Rongguang Wei <weirongguang@kylinos.cn>
> ---
>  drivers/pci/hotplug/pciehp_ctrl.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
> index 529c34808440..86fc9342be68 100644
> --- a/drivers/pci/hotplug/pciehp_ctrl.c
> +++ b/drivers/pci/hotplug/pciehp_ctrl.c
> @@ -232,6 +232,7 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
>  	 */
>  	mutex_lock(&ctrl->state_lock);
>  	switch (ctrl->state) {
> +	case BLINKINGON_STATE:
>  	case BLINKINGOFF_STATE:
>  		cancel_delayed_work(&ctrl->button_work);
>  		fallthrough;
> @@ -261,9 +262,6 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
>  	}
>  
>  	switch (ctrl->state) {
> -	case BLINKINGON_STATE:
> -		cancel_delayed_work(&ctrl->button_work);
> -		fallthrough;
>  	case OFF_STATE:
>  		ctrl->state = POWERON_STATE;
>  		mutex_unlock(&ctrl->state_lock);
> -- 
> 2.25.1
> 
> 
> No virus found
> 		Checked by Hillstone Network AntiVirus
>