ACK: [PATCH 0/2][SRU][OEM-5.6] pci: Speed up the process of s3 resume

[You-Sheng Yang]

Clean cherry-pick, merged by upstream.

Acked-by: You-Sheng Yang <vicamo.yang at canonical.com>

On 2020-05-29 00:47, Koba Ko wrote:
> BugLink: https://bugs.launchpad.net/bugs/1876844
> 
> [Impact]
> Process of s3 resume take 7s and it's too long which is over 5s.
> 
> [Fix]
> Instead of using the supported speeds to determine whether to wait for 
> Link training, check whether the port supports DLL Link Active reporting. 
> The ports in question do not, so we'll wait only the 100 ms required for Ports 
> that support Link speeds <= 5 GT/s.
> 
> This of course assumes these Ports always train the Link within 100 ms even 
> if they are operating at > 5 GT/s, which is not required by the spec.
> 
> [test]
> With the patch, the total time s3 resume is 4454.244 ms which is smaller than 5s.
> 
> [Regression Potential]
> Low. Follow the PCI spec to check whether the device supports DLL Link Active 
> reporting, then choose the time of delay.
> 
> Bjorn Helgaas (1):
>   PCI/PM: Adjust pcie_wait_for_link_delay() for caller delay
> 
> Mika Westerberg (1):
>   PCI/PM: Assume ports without DLL Link Active train links in 100 ms
> 
>  drivers/pci/pci.c | 34 +++++++++++++++++++++++-----------
>  1 file changed, 23 insertions(+), 11 deletions(-)
> 

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