Re: [PATCH 3/8] PCI: qcom: Do not advertise hotplug capability for IPs v2.7.0 and v1.9.0

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 06/05/2023 15:01, Dmitry Baryshkov wrote:
> On 06/05/2023 10:31, Manivannan Sadhasivam wrote:
>> SoCs making use of Qcom PCIe controller IPs v2.7.0 and v1.9.0 do not
>> support hotplug functionality. But the hotplug capability bit is set by
>> default in the hardware. This causes the kernel PCI core to register
>> hotplug service for the controller and send hotplug commands to it. But
>> those commands will timeout generating messages as below during boot and
>> suspend/resume.
>>
>> [    5.782159] pcieport 0001:00:00.0: pciehp: Timeout on hotplug 
>> command 0x03c0 (issued 2020 msec ago)
>> [    5.810161] pcieport 0001:00:00.0: pciehp: Timeout on hotplug 
>> command 0x03c0 (issued 2048 msec ago)
>> [    7.838162] pcieport 0001:00:00.0: pciehp: Timeout on hotplug 
>> command 0x07c0 (issued 2020 msec ago)
>> [    7.870159] pcieport 0001:00:00.0: pciehp: Timeout on hotplug 
>> command 0x07c0 (issued 2052 msec ago)
>>
>> This not only spams the console output but also induces a delay of a
>> couple of seconds. To fix this issue, let's clear the HPC bit in
>> PCI_EXP_SLTCAP register as a part of the post init sequence to not
>> advertise the hotplug capability for the controller.
>>
>> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>> ---
>>   drivers/pci/controller/dwc/pcie-qcom.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@gmail.com>
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>


-- 
With best wishes
Dmitry