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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,
	skhan@linuxfoundation.org
Subject: [PATCH v4 03/25] PCI: Use PCI_SET_ERROR_RESPONSE() when device not found
Date: Thu, 18 Nov 2021 19:33:13 +0530	[thread overview]
Message-ID: <29db0a6874716db80757e4e3cdd03562f13eb0cb.1637243717.git.naveennaidu479@gmail.com> (raw)
In-Reply-To: <cover.1637243717.git.naveennaidu479@gmail.com>

An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error. There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.

Use PCI_SET_ERROR_RESPONSE() to set the error response, when a faulty
read occurs.

This helps unify PCI error response checking and make error check
consistent and easier to find.

Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
 drivers/pci/access.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index eac0765d8bed..e1add90494ec 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -529,7 +529,7 @@ EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
 int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
 {
 	if (pci_dev_is_disconnected(dev)) {
-		*val = ~0;
+		PCI_SET_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 	return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
@@ -539,7 +539,7 @@ EXPORT_SYMBOL(pci_read_config_byte);
 int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
 {
 	if (pci_dev_is_disconnected(dev)) {
-		*val = ~0;
+		PCI_SET_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 	return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
@@ -550,7 +550,7 @@ int pci_read_config_dword(const struct pci_dev *dev, int where,
 					u32 *val)
 {
 	if (pci_dev_is_disconnected(dev)) {
-		*val = ~0;
+		PCI_SET_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 	return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
-- 
2.25.1


  parent reply	other threads:[~2021-11-18 14:05 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-18 14:03 [PATCH v4 00/25] Unify PCI error response checking Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 01/25] PCI: Add PCI_ERROR_RESPONSE and it's related definitions Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 02/25] PCI: Set error response in config access defines when ops->read() fails Naveen Naidu
2021-11-18 14:03 ` Naveen Naidu [this message]
2021-11-18 14:03 ` [PATCH v4 04/25] PCI: Remove redundant error fabrication when device read fails Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 05/25] PCI: thunder: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 06/25] PCI: iproc: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 07/25] PCI: mediatek: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 08/25] PCI: exynos: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 09/25] PCI: histb: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 10/25] PCI: kirin: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 11/25] PCI: aardvark: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 12/25] PCI: mvebu: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 13/25] PCI: altera: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 14/25] PCI: rcar: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 15/25] PCI: rockchip: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 16/25] PCI/ERR: Use PCI_POSSIBLE_ERROR() to check read from hardware Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 17/25] PCI: vmd: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 18/25] PCI: pciehp: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 19/25] PCI/DPC: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 20/25] PCI/PME: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 21/25] PCI: cpqphp: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 22/25] PCI: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 23/25] PCI: keystone: " Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 24/25] PCI: hv: Use PCI_ERROR_RESPONSE to specify hardware read error Naveen Naidu
2021-11-18 14:03 ` [PATCH v4 25/25] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
2021-11-18 20:44 ` [PATCH v4 00/25] Unify PCI error response checking Bjorn Helgaas

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