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From:   Naveen Naidu <naveennaidu479@gmail.com>
To:     bhelgaas@google.com
Cc:     Naveen Naidu <naveennaidu479@gmail.com>,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Toan Le <toan@os.amperecomputing.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        linux-arm-kernel@lists.infradead.org (moderated list:PCI DRIVER FOR
        APPLIEDMICRO XGENE)
Subject: [PATCH 22/22] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error
Date:   Mon, 11 Oct 2021 23:43:19 +0530
Message-Id: <afbff1fb626206fed8dd73bfde0f836abc2c03b2.1633972263.git.naveennaidu479@gmail.com>
In-Reply-To: <cover.1633972263.git.naveennaidu479@gmail.com>
References: <cover.1633972263.git.naveennaidu479@gmail.com>
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Include PCI_ERROR_RESPONSE along with 0xffffffff in the comment to
specify a hardware error. This makes finding where MMIO read error
occurs easier.

Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
 drivers/pci/controller/pci-xgene.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
index e64536047b65..4b10794e1ba1 100644
--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -176,10 +176,10 @@ static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
 	 * Retry Status (CRS) logic: when CRS Software Visibility is
 	 * enabled and we read the Vendor and Device ID of a non-existent
 	 * device, the controller fabricates return data of 0xFFFF0001
-	 * ("device exists but is not ready") instead of 0xFFFFFFFF
-	 * ("device does not exist").  This causes the PCI core to retry
-	 * the read until it times out.  Avoid this by not claiming to
-	 * support CRS SV.
+	 * ("device exists but is not ready") instead of
+	 * 0xFFFFFFFF (PCI_ERROR_RESPONSE) ("device does not exist"). This causes
+	 * the PCI core to retry the read until it times out.
+	 * Avoid this by not claiming to support CRS SV.
 	 */
 	if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
 	    ((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
-- 
2.25.1