linux-kernel - [PATCH] nvme-pci: Add suspend quirk for HP mt645 thin client

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Message-Id: <20230706180653.761247-1-alexandru.gagniuc@hp.com>
Date:   Thu,  6 Jul 2023 18:06:53 +0000
From:   Alexandru Gagniuc <alexandru.gagniuc@...com>
To:     linux-nvme@...ts.infradead.org
Cc:     kbusch@...nel.org, axboe@...com, hch@....de, sagi@...mberg.me,
        linux-kernel@...r.kernel.org, eniac-xw.zhang@...com,
        Alexandru Gagniuc <alexandru.gagniuc@...com>,
        stable@...r.kernel.org
Subject: [PATCH] nvme-pci: Add suspend quirk for HP mt645 thin client

The HP Elite mt645 thin client exhibits resume times of over one
minute when using the normal nvme resume path. BIOS has tried to work
around this by setting the "StorageD3Enable" ACPI property, but only
if it detected the "Linux-HPI-Hybrid-Graphics" _OSI() flag. This flag
does not exist, so the BIOS workaround can't work.

Instead, just set NVME_QUIRK_SIMPLE_SUSPEND when running on an mt645.
The DMI_PRODUCT_NAME cannot be used because this string can be changed
in the field. Match against DMI_BOARD_NAME, which should be immutable.

Cc: stable@...r.kernel.org
Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@...com>
---
 drivers/nvme/host/pci.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 492f319ebdf3..25b59f5ce874 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2897,6 +2897,15 @@ static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
 		if ((dmi_match(DMI_BOARD_VENDOR, "LENOVO")) &&
 		     dmi_match(DMI_BOARD_NAME, "LNVNB161216"))
 			return NVME_QUIRK_SIMPLE_SUSPEND;
+	} else if (dmi_match(DMI_SYS_VENDOR, "HP") &&
+		   (dmi_match(DMI_BOARD_NAME, "8B0F") ||
+		    dmi_match(DMI_BOARD_NAME, "8B59"))) {
+		/*
+		 * Force simple suspend to work around long resume latencies
+		 * (1 minute or longer).
+		 */
+		dev_info(&pdev->dev, "simple suspend quirk for HP mt645\n");
+		return NVME_QUIRK_SIMPLE_SUSPEND;
 	}
 
 	return 0;
-- 
2.39.1