Patch "nvme-pci: disable APST on Samsung SSD 960 EVO + ASUS PRIME B350M-A" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

nvme-pci: disable APST on Samsung SSD 960 EVO + ASUS PRIME B350M-A

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     nvme-pci-disable-apst-on-samsung-ssd-960-evo-asus-prime-b350m-a.patch

and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Kai-Heng Feng <[email protected]>
Date: Thu, 9 Nov 2017 01:12:03 -0500
Subject: nvme-pci: disable APST on Samsung SSD 960 EVO + ASUS PRIME B350M-A

From: Kai-Heng Feng <[email protected]>

[ Upstream commit 8427bbc224863e14d905c87920d4005cb3e88ac3 ]

The NVMe device in question drops off the PCIe bus after system suspend. I've tried several approaches to workaround this issue, but none of them works:
- NVME_QUIRK_DELAY_BEFORE_CHK_RDY
- NVME_QUIRK_NO_DEEPEST_PS
- Disable APST before controller shutdown
- Delay between controller shutdown and system suspend
- Explicitly set power state to 0 before controller shutdown

Fortunately it's a desktop, so disable APST won't hurt the battery.

Also, change the quirk function name to reflect it's for vendor combination quirks.

---
 drivers/nvme/host/pci.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

@@ -2282,7 +2282,7 @@ static int nvme_dev_map(struct nvme_dev
 	return -ENODEV;
 }
 
-static unsigned long check_dell_samsung_bug(struct pci_dev *pdev)
+static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
 {
 	if (pdev->vendor == 0x144d && pdev->device == 0xa802) {
 		/*

@@ -2297,6 +2297,14 @@ static unsigned long check_dell_samsung_
 		    (dmi_match(DMI_PRODUCT_NAME, "XPS 15 9550") ||
 		     dmi_match(DMI_PRODUCT_NAME, "Precision 5510")))
 			return NVME_QUIRK_NO_DEEPEST_PS;
+	} else if (pdev->vendor == 0x144d && pdev->device == 0xa804) {
+		/*
+		 * Samsung SSD 960 EVO drops off the PCIe bus after system
+		 * suspend on a Ryzen board, ASUS PRIME B350M-A.
+		 */
+		if (dmi_match(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC.") &&
+		    dmi_match(DMI_BOARD_NAME, "PRIME B350M-A"))
+			return NVME_QUIRK_NO_APST;
 	}
 
 	return 0;

@@ -2336,7 +2344,7 @@ static int nvme_probe(struct pci_dev *pd
 	if (result)
 		goto unmap;
 
-	quirks |= check_dell_samsung_bug(pdev);
+	quirks |= check_vendor_combination_bug(pdev);
 
 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
 			quirks);

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/nvme-pci-disable-apst-on-samsung-ssd-960-evo-asus-prime-b350m-a.patch