Re: [PATCH] HID: intel-ish-hid: Replace PCI_DEV_FLAGS_NO_D3 with pci_save_state

From: Kai-Heng Feng
Date: Thu May 21 2020 - 00:43:25 EST


Hi Srinivas,

> On May 9, 2020, at 01:45, Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
>
> On Tue, 2020-05-05 at 21:17 +0800, Kai-Heng Feng wrote:
>> PCI_DEV_FLAGS_NO_D3 should not be used outside of PCI core.
>>
>> Instead, we can use pci_save_state() to hint PCI core that the device
>> should stay at D0 during suspend.
>
> Your changes are doing more than just changing the flag. Can you
> explain more about the other changes?

By using pci_save_state(), in addition to keep itself stay at D0, the parent bridge will also stay at D0.
So it's a better approach to achieve the same thing.

> Also make sure that you test on both platforms which has regular S3 and
> S0ix (modern standby system).

Actually I don't have any physical hardware to test the patch, I found the issue when I search for D3 quirks through the source code.

Can you guys do a quick smoketest for this patch?

Kai-Heng

>
> Thanks,
> Srinivas
>
>
>>
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
>> ---
>> drivers/hid/intel-ish-hid/ipc/pci-ish.c | 15 ++++++++++-----
>> 1 file changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
>> b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
>> index f491d8b4e24c..ab588b9c8d09 100644
>> --- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
>> +++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
>> @@ -106,6 +106,11 @@ static inline bool ish_should_enter_d0i3(struct
>> pci_dev *pdev)
>> return !pm_suspend_via_firmware() || pdev->device ==
>> CHV_DEVICE_ID;
>> }
>>
>> +static inline bool ish_should_leave_d0i3(struct pci_dev *pdev)
>> +{
>> + return !pm_resume_via_firmware() || pdev->device ==
>> CHV_DEVICE_ID;
>> +}
>> +
>> /**
>> * ish_probe() - PCI driver probe callback
>> * @pdev: pci device
>> @@ -215,9 +220,7 @@ static void __maybe_unused
>> ish_resume_handler(struct work_struct *work)
>> struct ishtp_device *dev = pci_get_drvdata(pdev);
>> int ret;
>>
>> - /* Check the NO_D3 flag to distinguish the resume paths */
>> - if (pdev->dev_flags & PCI_DEV_FLAGS_NO_D3) {
>> - pdev->dev_flags &= ~PCI_DEV_FLAGS_NO_D3;
>> + if (ish_should_leave_d0i3(pdev) && !dev->suspend_flag) {
>> disable_irq_wake(pdev->irq);
>>
>> ishtp_send_resume(dev);
>> @@ -281,8 +284,10 @@ static int __maybe_unused ish_suspend(struct
>> device *device)
>> */
>> ish_disable_dma(dev);
>> } else {
>> - /* Set the NO_D3 flag, the ISH would enter D0i3
>> */
>> - pdev->dev_flags |= PCI_DEV_FLAGS_NO_D3;
>> + /* Save state so PCI core will keep the device
>> at D0,
>> + * the ISH would enter D0i3
>> + */
>> + pci_save_state(pdev);
>>
> Did you test on some C
>
>
>> enable_irq_wake(pdev->irq);
>> }