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[0/2] Fix some hotplug event issues

Message ID 20220921145434.21659-1-mario.limonciello@amd.com (mailing list archive)
Headers show
Series Fix some hotplug event issues | expand

Message

Mario Limonciello Sept. 21, 2022, 2:54 p.m. UTC
On AMD Pink Sardine it's been observed that if another CM has run before
the Linux CM that some registers may not match expectations which leads
to a non-functional hotplug for PCIe devices.

Explicitly set these registers that have been observed to cause problems
with hotplug to the defaults of the USB4 spec.

Mario Limonciello (2):
  thunderbolt: Explicitly reset plug events delay back to USB4 spec
    value
  thunderbolt: Explicitly enable lane adapter hotplug events at startup

 drivers/thunderbolt/switch.c  |  5 +++++
 drivers/thunderbolt/tb.h      |  1 +
 drivers/thunderbolt/tb_regs.h |  1 +
 drivers/thunderbolt/usb4.c    | 19 +++++++++++++++++++
 4 files changed, 26 insertions(+)

Comments

Greg KH Sept. 21, 2022, 3:45 p.m. UTC | #1
On Wed, Sep 21, 2022 at 09:54:31AM -0500, Mario Limonciello wrote:
> On AMD Pink Sardine it's been observed that if another CM has run before
> the Linux CM that some registers may not match expectations which leads
> to a non-functional hotplug for PCIe devices.
> 
> Explicitly set these registers that have been observed to cause problems
> with hotplug to the defaults of the USB4 spec.
> 
> Mario Limonciello (2):
>   thunderbolt: Explicitly reset plug events delay back to USB4 spec
>     value
>   thunderbolt: Explicitly enable lane adapter hotplug events at startup
> 
>  drivers/thunderbolt/switch.c  |  5 +++++
>  drivers/thunderbolt/tb.h      |  1 +
>  drivers/thunderbolt/tb_regs.h |  1 +
>  drivers/thunderbolt/usb4.c    | 19 +++++++++++++++++++
>  4 files changed, 26 insertions(+)

Any specific reason these were not tagged for stable backports?

thanks,

greg k-h
Mario Limonciello Sept. 21, 2022, 3:48 p.m. UTC | #2
On 9/21/2022 10:45, Greg KH wrote:
> On Wed, Sep 21, 2022 at 09:54:31AM -0500, Mario Limonciello wrote:
>> On AMD Pink Sardine it's been observed that if another CM has run before
>> the Linux CM that some registers may not match expectations which leads
>> to a non-functional hotplug for PCIe devices.
>>
>> Explicitly set these registers that have been observed to cause problems
>> with hotplug to the defaults of the USB4 spec.
>>
>> Mario Limonciello (2):
>>    thunderbolt: Explicitly reset plug events delay back to USB4 spec
>>      value
>>    thunderbolt: Explicitly enable lane adapter hotplug events at startup
>>
>>   drivers/thunderbolt/switch.c  |  5 +++++
>>   drivers/thunderbolt/tb.h      |  1 +
>>   drivers/thunderbolt/tb_regs.h |  1 +
>>   drivers/thunderbolt/usb4.c    | 19 +++++++++++++++++++
>>   4 files changed, 26 insertions(+)
> 
> Any specific reason these were not tagged for stable backports?
> 
> thanks,
> 
> greg k-h


No; no particular reason.  If Mika agrees with them, I think they are 
good candidates to include for stable too.  If I respin them, I'll tag 
accordingly.  If Mika picks them up as v1 I think he can add the tag 
when committing them.
Mika Westerberg Sept. 22, 2022, 11:34 a.m. UTC | #3
Hi Mario,

On Wed, Sep 21, 2022 at 10:48:17AM -0500, Limonciello, Mario wrote:
> On 9/21/2022 10:45, Greg KH wrote:
> > On Wed, Sep 21, 2022 at 09:54:31AM -0500, Mario Limonciello wrote:
> > > On AMD Pink Sardine it's been observed that if another CM has run before
> > > the Linux CM that some registers may not match expectations which leads
> > > to a non-functional hotplug for PCIe devices.
> > > 
> > > Explicitly set these registers that have been observed to cause problems
> > > with hotplug to the defaults of the USB4 spec.
> > > 
> > > Mario Limonciello (2):
> > >    thunderbolt: Explicitly reset plug events delay back to USB4 spec
> > >      value
> > >    thunderbolt: Explicitly enable lane adapter hotplug events at startup
> > > 
> > >   drivers/thunderbolt/switch.c  |  5 +++++
> > >   drivers/thunderbolt/tb.h      |  1 +
> > >   drivers/thunderbolt/tb_regs.h |  1 +
> > >   drivers/thunderbolt/usb4.c    | 19 +++++++++++++++++++
> > >   4 files changed, 26 insertions(+)
> > 
> > Any specific reason these were not tagged for stable backports?
> > 
> > thanks,
> > 
> > greg k-h
> 
> 
> No; no particular reason.  If Mika agrees with them, I think they are good
> candidates to include for stable too.  If I respin them, I'll tag
> accordingly.  If Mika picks them up as v1 I think he can add the tag when
> committing them.

I applied the first one to my fixes branch and tagged it for stable. For
the second one, I have a couple of comments that I would like you to
address (sent in a separate email) ;-)