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

[Owen Yang]

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.

Signed-off-by: Owen Yang <ecs.taipeikernel@xxxxxxxxx>
---

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