[PATCH] nvme-pci: add NVME_QUIRK_NO_DEEPEST_PS for Lexar NQ790

[Platon Miller]

The Lexar SSD NQ790 (PCI ID 1d97:5236, firmware 1.7.O.4F) advertises
a non-operational power state PS4 with 70000us exit latency. When the
controller enters PS4 via APST, it experiences significant latency
resuming from sleep and gets stuck reporting 100% active/busy time,
leading to noticeable I/O latency spikes in userspace.

Add NVME_QUIRK_NO_DEEPEST_PS to nvme_id_table for this device to prevent
it from entering PS4, while retaining shallower power-saving states.

Signed-off-by: Platon Miller <platon.ksenzenkokk at gmail.com>
---
 drivers/nvme/host/pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f8088d5aa..5414b16d4 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -4508,6 +4508,8 @@ static const struct pci_device_id nvme_id_table[] = {
 	{ PCI_DEVICE(0x1d97, 0x2269), /* Lexar NM760 */
 		.driver_data = NVME_QUIRK_BOGUS_NID |
 				NVME_QUIRK_IGNORE_DEV_SUBNQN, },
+	{ PCI_DEVICE(0x1d97, 0x5236), /* Lexar NQ790 / NM800 PRO */
+		.driver_data = NVME_QUIRK_NO_DEEPEST_PS, },
 	{ PCI_DEVICE(0x10ec, 0x5763), /* TEAMGROUP T-FORCE CARDEA ZERO Z330 SSD */
 		.driver_data = NVME_QUIRK_BOGUS_NID, },
 	{ PCI_DEVICE(0x1e4b, 0x1602), /* HS-SSD-FUTURE 2048G  */
-- 
2.56.0