[PATCH 4.12 04/43] usb:xhci:Fix regression when ATI chipsets detected - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Ben Hutchings <ben@decadent.org.uk>,
	Nehal Shah <Nehal-bakulchandra.Shah@amd.com>,
	Sandeep Singh <Sandeep.Singh@amd.com>,
	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Subject: [PATCH 4.12 04/43] usb:xhci:Fix regression when ATI chipsets detected
Date: Fri,  8 Sep 2017 15:18:52 +0200	[thread overview]
Message-ID: <20170908131826.727447045@linuxfoundation.org> (raw)
In-Reply-To: <20170908131826.555428826@linuxfoundation.org>

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sandeep Singh <sandeep.singh@amd.com>

commit e6b422b88b46353cf596e0db6dc0e39d50d90d6e upstream.

The following commit cause a regression on ATI chipsets.
'commit e788787ef4f9 ("usb:xhci:Add quirk for Certain
failing HP keyboard on reset after resume")'

This causes pinfo->smbus_dev to be wrongly set to NULL on
systems with the ATI chipset that this function checks for first.

Added conditional check for AMD chipsets to avoid the overwriting
pinfo->smbus_dev.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: e788787ef4f9 ("usb:xhci:Add quirk for Certain
failing HP keyboard on reset after resume")
cc: Nehal Shah <Nehal-bakulchandra.Shah@amd.com>
Signed-off-by: Sandeep Singh <Sandeep.Singh@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/host/pci-quirks.c |   35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -142,29 +142,30 @@ static int amd_chipset_sb_type_init(stru
 			pinfo->sb_type.gen = AMD_CHIPSET_SB700;
 		else if (rev >= 0x40 && rev <= 0x4f)
 			pinfo->sb_type.gen = AMD_CHIPSET_SB800;
-	}
-	pinfo->smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
-					  0x145c, NULL);
-	if (pinfo->smbus_dev) {
-		pinfo->sb_type.gen = AMD_CHIPSET_TAISHAN;
 	} else {
 		pinfo->smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
 				PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, NULL);
 
-		if (!pinfo->smbus_dev) {
-			pinfo->sb_type.gen = NOT_AMD_CHIPSET;
-			return 0;
+		if (pinfo->smbus_dev) {
+			rev = pinfo->smbus_dev->revision;
+			if (rev >= 0x11 && rev <= 0x14)
+				pinfo->sb_type.gen = AMD_CHIPSET_HUDSON2;
+			else if (rev >= 0x15 && rev <= 0x18)
+				pinfo->sb_type.gen = AMD_CHIPSET_BOLTON;
+			else if (rev >= 0x39 && rev <= 0x3a)
+				pinfo->sb_type.gen = AMD_CHIPSET_YANGTZE;
+		} else {
+			pinfo->smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
+							  0x145c, NULL);
+			if (pinfo->smbus_dev) {
+				rev = pinfo->smbus_dev->revision;
+				pinfo->sb_type.gen = AMD_CHIPSET_TAISHAN;
+			} else {
+				pinfo->sb_type.gen = NOT_AMD_CHIPSET;
+				return 0;
+			}
 		}
-
-		rev = pinfo->smbus_dev->revision;
-		if (rev >= 0x11 && rev <= 0x14)
-			pinfo->sb_type.gen = AMD_CHIPSET_HUDSON2;
-		else if (rev >= 0x15 && rev <= 0x18)
-			pinfo->sb_type.gen = AMD_CHIPSET_BOLTON;
-		else if (rev >= 0x39 && rev <= 0x3a)
-			pinfo->sb_type.gen = AMD_CHIPSET_YANGTZE;
 	}
-
 	pinfo->sb_type.rev = rev;
 	return 1;
 }
