APPLIED[G]: [PATCH 0/1][SRU][G/U/OEM-5.10] Fix disk probing under SATA controller behind VMD

[Kelsey Skunberg]

Applied to Groovy master-next. thank you! 

-Kelsey

On 2020-12-22 15:51:19 , You-Sheng Yang wrote:
> BugLink: https://bugs.launchpad.net/bugs/1894778
> 
> [Impact]
> 
> When booting with a certain platforms with boot disk attached to SATA
> bus behind Intel VMD controller, disk probing may fail with following
> error messages left in dmesg:
> 
>   [ 6.163286] ata1.00: qc timeout (cmd 0xec)
>   [ 6.165630] ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> 
> [Fix]
> 
> Upstream commit f6b7bb847ca8 ("PCI: vmd: Offset Client VMD MSI-X
> vectors") currently in vanilla kernel tree for v5.11.
> 
> [Test Case]
> 
> Check dmesg/lsblk for disk probe.
> 
> For pci MSI address, check lspci output:
> 
>   $ lspci -vvnn
>   ....
>       Capabilities: [80] MSI: Enable+ Count=1/1 maskable- 64bit-
>           Address: fee00000  Data: 0000
> 
> When it fails, the address is fee00000. And with a patched kernel:
> 
>   $ lspci -vvnn
>   ....
>       Capabilities: [80] MSI: Enable+ Count=1/1 maskable- 64bit-
>           Address: fee01000  Data: 0000
> 
> [Where problems could occur]
> 
> An unpatched kernel will not be able to probe SATA controllers moved
> behind VMD when VMD/RAID mode is enabled in BIOS, leaving disks
> attached on it completely unusable. With this change, kernel would
> then be able to probe them but may also suffer from issues that only
> occur under such configuration. However, the worst case is to move away
> sata disks from VMD bus as they are currently without this fix, so the
> risk here should be justified.
> 
> Jon Derrick (1):
>   PCI: vmd: Offset Client VMD MSI-X vectors
> 
>  drivers/pci/controller/vmd.c | 37 +++++++++++++++++++++++++-----------
>  1 file changed, 26 insertions(+), 11 deletions(-)
> 
> -- 
> 2.29.2
> 
> 
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