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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,
	"Krzysztof Wilczyński" <kw@linux.com>
Subject: [PATCH 19/22] PCI: cpqphp: Use RESPONSE_IS_PCI_ERROR() to check read from hardware
Date: Mon, 11 Oct 2021 23:41:09 +0530	[thread overview]
Message-ID: <e330cad6bdc0fc932a72d33b221f1b51ab55fcfe.1633972263.git.naveennaidu479@gmail.com> (raw)
In-Reply-To: <cover.1633972263.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..d5274b9b06a5 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:[~2021-10-11 18:11 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-11 17:35 [PATCH 00/22] PCI: Unify PCI error response checking Naveen Naidu
2021-10-11 17:37 ` [PATCH 01/22] PCI: Add PCI_ERROR_RESPONSE and it's related defintions Naveen Naidu
2021-10-11 17:38 ` [PATCH 02/22] PCI: Unify PCI error response checking Naveen Naidu
2021-10-11 22:05   ` Rob Herring
2021-10-12 16:21     ` Naveen Naidu
2021-10-12 18:02       ` Rob Herring
2021-10-12 22:52       ` Pali Rohár
2021-10-13  2:43     ` Bjorn Helgaas
2021-10-13 13:06       ` Rob Herring
2021-10-13 17:16         ` Naveen Naidu
2021-10-13 17:54           ` Pali Rohár
2021-10-13 18:48           ` Bjorn Helgaas
2021-10-13 21:47           ` Rob Herring
2021-10-13 22:03             ` Pali Rohár
2021-10-13 22:12             ` Bjorn Helgaas
2021-10-11 17:45 ` [PATCH 03/22] PCI: thunder: Use SET_PCI_ERROR_RESPONSE() when device not found Naveen Naidu
2021-10-11 17:46 ` [PATCH 04/22] PCI: iproc: " Naveen Naidu
2021-10-11 17:51 ` [PATCH 05/22] PCI: mediatek: " Naveen Naidu
2021-10-11 17:52 ` [PATCH 06/22] PCI: exynos: " Naveen Naidu
2021-10-11 17:53 ` [PATCH 07/22] PCI: histb: " Naveen Naidu
2021-10-11 17:55 ` [PATCH 08/22] PCI: kirin: " Naveen Naidu
2021-10-11 17:56 ` [PATCH 09/22] PCI: aardvark: " Naveen Naidu
2021-10-11 18:08   ` Pali Rohár
2021-10-11 18:28     ` Naveen Naidu
     [not found]     ` <20211011182526.kboaxqofdpd2jjrl@theprophet>
2021-10-11 18:41       ` Pali Rohár
2021-10-12 15:59         ` Naveen Naidu
2021-10-13  2:13           ` Bjorn Helgaas
2021-10-13 17:59             ` Pali Rohár
2021-10-11 18:00 ` [PATCH 10/22] PCI: mvebu: " Naveen Naidu
2021-10-11 18:00 ` [PATCH 11/22] PCI: altera: " Naveen Naidu
2021-10-11 18:02 ` [PATCH 12/22] PCI: rcar: " Naveen Naidu
2021-10-11 18:02 ` [PATCH 13/22] PCI: rockchip: " Naveen Naidu
2021-10-11 18:04 ` [PATCH 14/22] PCI/ERR: Use RESPONSE_IS_PCI_ERROR() to check read from hardware Naveen Naidu
2021-10-11 18:06 ` [PATCH 15/22] PCI: vmd: " Naveen Naidu
2021-10-14 18:04   ` Jonathan Derrick
2021-10-11 18:07 ` [PATCH 16/22] PCI: pciehp: " Naveen Naidu
2021-10-11 19:47   ` Lukas Wunner
2021-10-12 16:05     ` Naveen Naidu
2021-10-12 23:12       ` Pali Rohár
2021-10-13 12:20         ` Lukas Wunner
2021-10-11 18:08 ` [PATCH 17/22] PCI/DPC: " Naveen Naidu
2021-10-11 18:10 ` [PATCH 18/22] PCI/PME: " Naveen Naidu
2021-10-11 18:11 ` Naveen Naidu [this message]
2021-10-11 18:11 ` [PATCH 20/22] PCI: keystone: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
2021-10-11 18:12 ` [PATCH 21/22] PCI: hv: Use PCI_ERROR_RESPONSE to specify hardware read error Naveen Naidu
2021-10-11 18:13 ` [PATCH 22/22] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu

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