linux-kernel - Re: [PATCH v7 5/5] PCI/AER: Only clear error bits in pcie_clear_device

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Message-ID: <83411a03-e5f8-4f28-b781-b4010a785f1b@linux.alibaba.com>
Date: Fri, 6 Feb 2026 16:12:39 +0800
From: Shuai Xue <xueshuai@...ux.alibaba.com>
To: Lukas Wunner <lukas@...ner.de>
Cc: Jonathan Cameron <jonathan.cameron@...wei.com>,
 linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
 linuxppc-dev@...ts.ozlabs.org, bhelgaas@...gle.com, kbusch@...nel.org,
 sathyanarayanan.kuppuswamy@...ux.intel.com, mahesh@...ux.ibm.com,
 oohall@...il.com, terry.bowman@....com, tianruidong@...ux.alibaba.com
Subject: Re: [PATCH v7 5/5] PCI/AER: Only clear error bits in
 pcie_clear_device_status()



On 2/3/26 3:44 PM, Lukas Wunner wrote:
> On Wed, Jan 28, 2026 at 08:45:36PM +0800, Shuai Xue wrote:
>> The revised the commit message is:
>>
>> PCI/AER: Only clear error bits in PCIe Device Status register
>>
>> Currently, pcie_clear_device_status() clears the entire PCIe Device
>> Status register (PCI_EXP_DEVSTA), which includes both error status bits
>> and other status bits.
>>
>> According to PCIe Base Spec r6.0 sec 7.5.3.5, the Device Status register
>> contains different types of status bits:
> 
> Always cite the latest spec revision, i.e. PCIe r7.0 sec 7.5.3.5.

Sure, I will update the cite version.

> 
>> - RW1C (read/write 1 to clear) non-error bits: For example, Emergency
>>    Power Reduction Detected (bit 6). Unconditionally clearing these bits
>>    can interfere with other drivers or subsystems that rely on them.
> 
> It would be good to explicitly call out that this bit was introduced with
> PCIe r5.0 in 2019 and that it's currently the only writable bit in the
> register besides the error bits.

Sure, will add it.

> 
>> - Reserved bits: May be used for future features and should be preserved.
> 
> Wrong, they're marked "RsvdZ" (not "RsvdP"), so they're supposed to be
> written as zero (not preserved).

Thanks for correcting me. Will fix it.

> 
> Thanks,
> 
> Lukas


Thanks for valuable comments.
Shuai