From: Rob Herring <robh@kernel.org>
To: Naveen Naidu <naveennaidu479@gmail.com>
Cc: bhelgaas@google.com,
linux-kernel-mentees@lists.linuxfoundation.org,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 04/24] PCI: Remove redundant error fabrication when device read fails
Date: Wed, 20 Oct 2021 08:42:26 -0500 [thread overview]
Message-ID: <YXAcws0S2xBvjsDb@robh.at.kernel.org> (raw)
In-Reply-To: <0114a4a44ceacfbd6a7859d8613ca5942f5b35d7.1634306198.git.naveennaidu479@gmail.com>
On Fri, Oct 15, 2021 at 08:08:45PM +0530, Naveen Naidu wrote:
> 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.
>
> The host controller drivers sets the error response values (~0) and
> returns an error when faulty hardware read occurs. But the error
> response value (~0) is already being set in PCI_OP_READ and
> PCI_USER_READ_CONFIG whenever a read by host controller driver fails.
>
> Thus, it's no longer necessary for the host controller drivers to
> fabricate any error response.
>
> 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 | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
Reviewed-by: Rob Herring <robh@kernel.org>
next prev parent reply other threads:[~2021-10-20 13:42 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-15 14:35 [PATCH v2 00/24] Unify PCI error response checking Naveen Naidu
2021-10-15 14:28 ` [PATCH v2 01/24] PCI: Add PCI_ERROR_RESPONSE and it's related definitions Naveen Naidu
2021-10-20 13:24 ` Rob Herring
2021-10-15 14:28 ` [PATCH v2 02/24] PCI: Set error response in config access defines when ops->read() fails Naveen Naidu
2021-10-20 13:41 ` Rob Herring
2021-10-20 13:52 ` Pali Rohár
2021-10-20 15:13 ` Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 03/24] PCI: Unify PCI error response checking Naveen Naidu
2021-10-20 13:13 ` Rob Herring
2021-10-20 15:15 ` Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 04/24] PCI: Remove redundant error fabrication when device read fails Naveen Naidu
2021-10-20 13:42 ` Rob Herring [this message]
2021-10-15 14:38 ` [PATCH v2 05/24] PCI: thunder: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 06/24] PCI: iproc: " Naveen Naidu
2021-10-15 16:49 ` Ray Jui
2021-10-15 17:05 ` Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 07/24] PCI: mediatek: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 08/24] PCI: exynos: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 09/24] PCI: histb: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 10/24] PCI: kirin: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 11/24] PCI: aardvark: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 12/24] PCI: mvebu: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 13/24] PCI: altera: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 14/24] PCI: rcar: " Naveen Naidu
2021-10-18 11:32 ` Geert Uytterhoeven
2021-10-18 11:51 ` Naveen Naidu
2021-10-18 12:00 ` Geert Uytterhoeven
2021-10-15 14:38 ` [PATCH v2 15/24] PCI: rockchip: " Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 16/24] PCI/ERR: Use RESPONSE_IS_PCI_ERROR() to check read from hardware Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 17/24] PCI: vmd: " Naveen Naidu
2021-10-15 14:52 ` Naveen Naidu
2021-10-15 14:38 ` [PATCH v2 18/24] PCI: pciehp: " Naveen Naidu
2021-10-15 15:15 ` Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 19/24] PCI/DPC: " Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 20/24] PCI/PME: " Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 21/24] PCI: cpqphp: " Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 22/24] PCI: keystone: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 23/24] PCI: hv: Use PCI_ERROR_RESPONSE to specify hardware read error Naveen Naidu
2021-10-15 14:39 ` [PATCH v2 24/24] PCI: xgene: Use PCI_ERROR_RESPONSE to specify hardware error Naveen Naidu
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