[AMD Official Use Only] Hi all, After retrying suspend with this patch, get suspend test successfully and run over 1800 cycles I think that is test environment error before. Thanks Best Regard, Patrick -----Original Message----- From: Limonciello, Mario <Mario.Limonciello@xxxxxxx> Sent: Friday, March 18, 2022 10:43 AM To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; open list:PCI SUBSYSTEM <linux-pci@xxxxxxxxxxxxxxx>; open list <linux-kernel@xxxxxxxxxxxxxxx>; Huang, Patrick <Patrick.Huang@xxxxxxx> Subject: Re: [PATCH v2] PCI: Disable LTR on suspend for SSSTC 0x9100 +Patrick Huang On 3/17/22 08:10, Mario Limonciello wrote: > Some drives from SSSTC are showing stability problems after s0i3 entry > when the Linux kernel is in s2idle loop if LTR has been enabled. This > leads to failures to resume. > > This appears to be a firmware issue specific to SSSTC SSDs, so quirk > them to avoid LTR being enabled during the suspend process. > > Link: > https://lore.kernel.org/linux-nvme/20220315072233.GA2288@xxxxxx/T/#mb9 > b5782220a32e2c69fe37cf04ae1501b0f48221 > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> > --- > changes from v1->v2: > * Move into a PCI quirk, handle entirely in PCI subsystem > Patrick has been running stress tests with this patch and reported a failure. When it's figured out we will re-submit V3. If any concerns to this approach in V2 though, comments still welcome. Thanks, > drivers/pci/quirks.c | 17 +++++++++++++++++ > include/linux/pci_ids.h | 2 ++ > 2 files changed, 19 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index > d2dd6a6cda60..005142d574e7 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -5879,3 +5879,20 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1533, rom_bar_overlap_defect); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1536, rom_bar_overlap_defect); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1537, rom_bar_overlap_defect); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1538, > rom_bar_overlap_defect); > + > +/* > + * SSSTC firmware will continue to send LTR requests after device has > +entered D3 > + * > + * This behavior causes problems when entering/exit s2idle, so avoid > +letting LTR > + * be enabled during suspend. > + */ > +static void ssstc_disable_ltr(struct pci_dev *pdev) { > + pcie_capability_clear_word(pdev, PCI_EXP_DEVCTL2, > +PCI_EXP_DEVCTL2_LTR_EN); } static void ssstc_enable_ltr(struct > +pci_dev *pdev) { > + pcie_capability_set_word(pdev, PCI_EXP_DEVCTL2, > +PCI_EXP_DEVCTL2_LTR_EN); } > +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_SSSTC, 0x9100, > +ssstc_disable_ltr); DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_SSSTC, > +0x9100, ssstc_enable_ltr); > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index > 130949c3b486..ab47ccdd2ece 100644 > --- a/include/linux/pci_ids.h > +++ b/include/linux/pci_ids.h > @@ -2568,6 +2568,8 @@ > #define PCI_VENDOR_ID_TEKRAM 0x1de1 > #define PCI_DEVICE_ID_TEKRAM_DC290 0xdc29 > > +#define PCI_VENDOR_ID_SSSTC 0x1e95 > + > #define PCI_VENDOR_ID_TEHUTI 0x1fc9 > #define PCI_DEVICE_ID_TEHUTI_3009 0x3009 > #define PCI_DEVICE_ID_TEHUTI_3010 0x3010
