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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, "Krzysztof Wilczyński" <kw@linux.com>
Subject: [PATCH v3 21/25] PCI: cpqphp: Use RESPONSE_IS_PCI_ERROR() to check read from hardware
Date: Thu, 21 Oct 2021 20:37:46 +0530	[thread overview]
Message-ID: <20dd8fb823cdb1df4a6313fd5872d78d8f0860c0.1634825082.git.naveennaidu479@gmail.com> (raw)
In-Reply-To: <cover.1634825082.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 RESPONSE_IS_PCI_ERROR() to check the response we get when we read
data from hardware.

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

Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
 drivers/pci/hotplug/cpqphp_ctrl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/hotplug/cpqphp_ctrl.c b/drivers/pci/hotplug/cpqphp_ctrl.c
index 1b26ca0b3701..bf14391c005f 100644
--- a/drivers/pci/hotplug/cpqphp_ctrl.c
+++ b/drivers/pci/hotplug/cpqphp_ctrl.c
@@ -2273,7 +2273,7 @@ static u32 configure_new_device(struct controller  *ctrl, struct pci_func  *func
 		while ((function < max_functions) && (!stop_it)) {
 			pci_bus_read_config_dword(ctrl->pci_bus, PCI_DEVFN(func->device, function), 0x00, &ID);
 
-			if (ID == 0xFFFFFFFF) {
+			if (RESPONSE_IS_PCI_ERROR(ID)) {
 				function++;
 			} else {
 				/* Setup slot structure. */
@@ -2517,7 +2517,7 @@ static int configure_new_function(struct controller *ctrl, struct pci_func *func
 			pci_bus_read_config_dword(pci_bus, PCI_DEVFN(device, 0), 0x00, &ID);
 			pci_bus->number = func->bus;
 
-			if (ID != 0xFFFFFFFF) {	  /*  device present */
+			if (!RESPONSE_IS_PCI_ERROR(ID)) {	  /*  device present */
 				/* Setup slot structure. */
 				new_slot = cpqhp_slot_create(hold_bus_node->base);
 
-- 
2.25.1


  parent reply	other threads:[~2021-10-21 15:15 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21 15:07 [PATCH v3 00/25] Unify PCI error response checking Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 01/25] PCI: Add PCI_ERROR_RESPONSE and it's related definitions Naveen Naidu
2021-10-21 16:08   ` Pali Rohár
2021-11-17 23:58   ` Bjorn Helgaas
2021-11-18 13:30     ` Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 02/25] PCI: Set error response in config access defines when ops->read() fails Naveen Naidu
2021-10-21 15:59   ` Pali Rohár
2021-10-21 15:07 ` [PATCH v3 03/25] PCI: Use SET_PCI_ERROR_RESPONSE() when device not found Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 04/25] PCI: Remove redundant error fabrication when device read fails Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 05/25] PCI: thunder: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 06/25] PCI: iproc: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 07/25] PCI: mediatek: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 08/25] PCI: exynos: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 09/25] PCI: histb: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 10/25] PCI: kirin: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 11/25] PCI: aardvark: " Naveen Naidu
2021-10-21 15:58   ` Pali Rohár
2021-10-21 15:07 ` [PATCH v3 12/25] PCI: mvebu: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 13/25] PCI: altera: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 14/25] PCI: rcar: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 15/25] PCI: rockchip: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 16/25] PCI/ERR: Use RESPONSE_IS_PCI_ERROR() to check read from hardware Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 17/25] PCI: vmd: " Naveen Naidu
2021-10-21 15:19   ` Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 18/25] PCI: pciehp: " Naveen Naidu
2021-10-21 15:22   ` Naveen Naidu
2021-10-22  7:01     ` Lukas Wunner
2021-10-21 15:07 ` [PATCH v3 19/25] PCI/DPC: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 20/25] PCI/PME: " Naveen Naidu
2021-10-21 15:07 ` Naveen Naidu [this message]
2021-10-21 15:07 ` [PATCH v3 22/25] PCI: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 23/25] PCI: keystone: " Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 24/25] PCI: hv: Use PCI_ERROR_RESPONSE to specify hardware read error Naveen Naidu
2021-10-21 15:07 ` [PATCH v3 25/25] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu

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