mbox series

[v2,0/8] PCI: qcom: Do not advertise hotplug capability

Message ID 20230519143117.23875-1-manivannan.sadhasivam@linaro.org
Headers show
Series PCI: qcom: Do not advertise hotplug capability | expand

Message

Manivannan Sadhasivam May 19, 2023, 2:31 p.m. UTC
Hi,

The SoCs making use of Qualcomm PCIe controllers do not support the PCIe 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, this series clears the HPC bit in PCI_EXP_SLTCAP
register as a part of the post init sequence for all IP versions to not
advertise the hotplug capability for the controller.

Testing
=======

This series has been tested on DB845c (SDM845 SoC) and Lenovo Thinkpad X13s
(SC8280XP SoC).

Thanks,
Mani

Changes in v2:

* Collected tags
* Moved the HPC clearing to a separate function and reused across different
  configs

Manivannan Sadhasivam (8):
  PCI: qcom: Use DWC helpers for modifying the read-only DBI registers
  PCI: qcom: Disable write access to read only registers for IP v2.9.0
  PCI: qcom: Do not advertise hotplug capability for IPs v2.7.0 and
    v1.9.0
  PCI: qcom: Do not advertise hotplug capability for IPs v2.3.3 and
    v2.9.0
  PCI: qcom: Do not advertise hotplug capability for IP v2.3.2
  PCI: qcom: Use post init sequence of IP v2.3.2 for v2.4.0
  PCI: qcom: Do not advertise hotplug capability for IP v1.0.0
  PCI: qcom: Do not advertise hotplug capability for IP v2.1.0

 drivers/pci/controller/dwc/pcie-qcom.c | 73 ++++++++++++++------------
 1 file changed, 38 insertions(+), 35 deletions(-)

Comments

Lorenzo Pieralisi May 22, 2023, 9:01 a.m. UTC | #1
On Fri, May 19, 2023 at 08:01:09PM +0530, Manivannan Sadhasivam wrote:
> Hi,
> 
> The SoCs making use of Qualcomm PCIe controllers do not support the PCIe 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, this series clears the HPC bit in PCI_EXP_SLTCAP
> register as a part of the post init sequence for all IP versions to not
> advertise the hotplug capability for the controller.
> 
> Testing
> =======
> 
> This series has been tested on DB845c (SDM845 SoC) and Lenovo Thinkpad X13s
> (SC8280XP SoC).
> 
> Thanks,
> Mani
> 
> Changes in v2:
> 
> * Collected tags
> * Moved the HPC clearing to a separate function and reused across different
>   configs
> 
> Manivannan Sadhasivam (8):
>   PCI: qcom: Use DWC helpers for modifying the read-only DBI registers
>   PCI: qcom: Disable write access to read only registers for IP v2.9.0
>   PCI: qcom: Do not advertise hotplug capability for IPs v2.7.0 and
>     v1.9.0
>   PCI: qcom: Do not advertise hotplug capability for IPs v2.3.3 and
>     v2.9.0
>   PCI: qcom: Do not advertise hotplug capability for IP v2.3.2
>   PCI: qcom: Use post init sequence of IP v2.3.2 for v2.4.0
>   PCI: qcom: Do not advertise hotplug capability for IP v1.0.0
>   PCI: qcom: Do not advertise hotplug capability for IP v2.1.0
> 
>  drivers/pci/controller/dwc/pcie-qcom.c | 73 ++++++++++++++------------
>  1 file changed, 38 insertions(+), 35 deletions(-)
> 

Some patches are signed-off twice, FYI, I can fix that while
applying.

Lorenzo

> -- 
> 2.25.1
>
Manivannan Sadhasivam May 29, 2023, 8:58 a.m. UTC | #2
On Mon, May 22, 2023 at 11:01:17AM +0200, Lorenzo Pieralisi wrote:
> On Fri, May 19, 2023 at 08:01:09PM +0530, Manivannan Sadhasivam wrote:
> > Hi,
> > 
> > The SoCs making use of Qualcomm PCIe controllers do not support the PCIe 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, this series clears the HPC bit in PCI_EXP_SLTCAP
> > register as a part of the post init sequence for all IP versions to not
> > advertise the hotplug capability for the controller.
> > 
> > Testing
> > =======
> > 
> > This series has been tested on DB845c (SDM845 SoC) and Lenovo Thinkpad X13s
> > (SC8280XP SoC).
> > 
> > Thanks,
> > Mani
> > 
> > Changes in v2:
> > 
> > * Collected tags
> > * Moved the HPC clearing to a separate function and reused across different
> >   configs
> > 
> > Manivannan Sadhasivam (8):
> >   PCI: qcom: Use DWC helpers for modifying the read-only DBI registers
> >   PCI: qcom: Disable write access to read only registers for IP v2.9.0
> >   PCI: qcom: Do not advertise hotplug capability for IPs v2.7.0 and
> >     v1.9.0
> >   PCI: qcom: Do not advertise hotplug capability for IPs v2.3.3 and
> >     v2.9.0
> >   PCI: qcom: Do not advertise hotplug capability for IP v2.3.2
> >   PCI: qcom: Use post init sequence of IP v2.3.2 for v2.4.0
> >   PCI: qcom: Do not advertise hotplug capability for IP v1.0.0
> >   PCI: qcom: Do not advertise hotplug capability for IP v2.1.0
> > 
> >  drivers/pci/controller/dwc/pcie-qcom.c | 73 ++++++++++++++------------
> >  1 file changed, 38 insertions(+), 35 deletions(-)
> > 
> 
> Some patches are signed-off twice, FYI, I can fix that while
> applying.
> 

Sorry for that! I used b4 to apply these patches and that added additional
signed-off-by tag for all patches. Since Dmitry also requested to remove his
gmail tag, I can spin another version once we sort out the comment on patch
2/8.

- Mani

> Lorenzo
> 
> > -- 
> > 2.25.1
> >