From: Saheed Bolarinwa <refactormyself@gmail•com>
To: Borislav Petkov <bp@alien8•de>, trix@redhat•com
Cc: helgaas@kernel•org, Kalle Valo <kvalo@codeaurora•org>,
"David S. Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>,
Wolfgang Grandegger <wg@grandegger•com>,
Marc Kleine-Budde <mkl@pengutronix•de>,
Miquel Raynal <miquel.raynal@bootlin•com>,
Richard Weinberger <richard@nod•at>,
Vignesh Raghavendra <vigneshr@ti•com>,
Joerg Roedel <joro@8bytes•org>,
bjorn@helgaas•com, skhan@linuxfoundation•org,
linux-kernel-mentees@lists•linuxfoundation.org,
linux-pci@vger•kernel.org, linux-kernel@vger•kernel.org,
linux-wireless@vger•kernel.org, netdev@vger•kernel.org,
linux-mtd@lists•infradead.org, iommu@lists•linux-foundation.org,
linux-rdma@vger•kernel.org, linux-ide@vger•kernel.org,
linux-i2c@vger•kernel.org, linux-hwmon@vger•kernel.org,
dri-devel@lists•freedesktop.org, intel-gfx@lists•freedesktop.org,
linux-gpio@vger•kernel.org, linux-fpga@vger•kernel.org,
linux-edac@vger•kernel.org, dmaengine@vger•kernel.org,
linux-crypto@vger•kernel.org,
linux-atm-general@lists•sourceforge.net
Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value
Date: Sun, 2 Aug 2020 19:28:00 +0200 [thread overview]
Message-ID: <b720aa44-895a-203b-e220-ecdb3acd9278@gmail.com> (raw)
In-Reply-To: <20200801125657.GA25391@nazgul.tnic>
On 8/1/20 2:56 PM, Borislav Petkov wrote:
> On Sat, Aug 01, 2020 at 01:24:29PM +0200, Saheed O. Bolarinwa wrote:
>> The return value of pci_read_config_*() may not indicate a device error.
>> However, the value read by these functions is more likely to indicate
>> this kind of error. This presents two overlapping ways of reporting
>> errors and complicates error checking.
> So why isn't the *value check done in the pci_read_config_* functions
> instead of touching gazillion callers?
Because the value ~0 has a meaning to some drivers and only
drivers have this knowledge. For those cases more checks will
be needed to ensure that it is an error that has actually
happened.
> For example, pci_conf{1,2}_read() could check whether the u32 *value it
> just read depending on the access method, whether that value is ~0 and
> return proper PCIBIOS_ error in that case.
The primary goal is to make pci_config_read*() return void, so
that there is *only* one way to check for error i.e. through the
obtained value.
Again, only the drivers can determine if ~0 is a valid value. This
information is not available inside pci_config_read*().
- Saheed
next prev parent reply other threads:[~2020-08-02 18:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-01 11:24 [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value Saheed O. Bolarinwa
2020-08-01 11:24 ` [RFC PATCH 02/17] atm: " Saheed O. Bolarinwa
2020-08-01 11:24 ` [RFC PATCH 17/17] net: " Saheed O. Bolarinwa
2020-08-01 12:56 ` [RFC PATCH 00/17] " Borislav Petkov
2020-08-02 14:53 ` Tom Rix
2020-08-02 17:28 ` Saheed Bolarinwa [this message]
2020-08-02 18:46 ` Borislav Petkov
2020-08-02 19:14 ` Bjorn Helgaas
2020-08-02 20:18 ` Borislav Petkov
2020-08-03 6:56 ` Christoph Hellwig
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