Re: [PATCH v3] PCI: Add suspend fixup for SSD on sc7280

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Manivannan]

On Tue, May 30, 2023 at 10:26:29AM +0800, Owen Yang wrote:
> Implement this workaround to correct NVMe suspend process.
> 
> SSD will randomly crashed at 100~250+ suspend/resume cycle. Phison and
> Qualcomm found that its due to NVMe entering D3cold instead of L1ss.
> https://partnerissuetracker.corp.google.com/issues/275663637
> 
> According to Qualcomm. This issue has been found last year and they have
> attempt to submit some patches to fix the pci suspend behavior.
> (ref:https://patchwork.kernel.org/project/linux-arm-msm/list/?
> series=665060&state=%2A&archive=both).
> But somehow these patches were rejected because of its complexity. And
> we've got advise from Google that it will be more efficient that we
> implement a quirks to fix this issue.
> 
> The DECLARE_PCI_FIXUP_SUSPEND function has already specify the PCI device
> ID. And this SSD will only be used at our Chromebook device only.

I'll wait for your response to Manivannan:
https://lore.kernel.org/r/20230529164856.GE5633@thinkpad

If the issue is caused by an out-of-tree patch, this fix needs to stay
with that patch.  If the issue doesn't happen with the current
upstream kernel, this patch isn't relevant for upstream.

> Signed-off-by: Owen Yang <ecs.taipeikernel@gmail.com>
> ---
> 
> Changes in v3:
> - Adjust comment about issue behavior, ASPM, and the sc7280 connection.
> - Fix multi-line code comment.
> 
> Changes in v2:
> - Fix subject line style from "drivers: pci: quirks:" to "PCI:"
> - Adjust comment.
> 
>  drivers/pci/quirks.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index f4e2a88729fd..6d895a4da4b5 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5945,6 +5945,21 @@ static void nvidia_ion_ahci_fixup(struct pci_dev *pdev)
>  }
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x0ab8, nvidia_ion_ahci_fixup);
>  
> +/* 
> + * In Qualcomm 7c gen 3 sc7280 platform. Some of the SSD will enter
> + * D3cold instead of L1ss.It cause the device will randomly crash after
> + * suspend within 100~250+ cycles of suspend/resume test.
> + *
> + * After adding this fixup.We've verified that 10 devices passed
> + * the suspend/resume 2500 cycles test.
> + */
> +static void phison_suspend_fixup(struct pci_dev *pdev)
> +{
> +	msleep(30);
> +}
> +DECLARE_PCI_FIXUP_SUSPEND(0x1987, 0x5013, phison_suspend_fixup);
> +DECLARE_PCI_FIXUP_SUSPEND(0x1987, 0x5015, phison_suspend_fixup);
> +
>  static void rom_bar_overlap_defect(struct pci_dev *dev)
>  {
>  	pci_info(dev, "working around ROM BAR overlap defect\n");
> -- 
> 2.17.1
>