Re: [PATCH v4] platform/x86/amd/pmc: adjust getting DRAM size behavior

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Thu, 16 Nov 2023, Shyam Sundar S K wrote:

> amd_pmc_get_dram_size() is used to get the DRAM size information. But in
> the current code, mailbox command to get the DRAM size info is sent based
> on the values of dev->major and dev->minor.
> 
> But dev->major and dev->minor will have either junk or zero assigned to
> them until at least once a call to amd_pmc_get_smu_version() is made which
> ideally populates dev->major and dev->minor.
> 
> Ideally to suffice this, adding a amd_pmc_get_smu_version() call to
> amd_pmc_get_dram_size() would solve, but that has a downside of elevating
> the boot times.
> 
> After talking to the PMFW team, its understood that the "get dram size"
> mbox command would only be supported on specific platforms (like Mendocino)
> and not all. So, adjust getting DRAM size behavior such that,
> 
> - if that's Rembrandt or Mendocino and the underlying PMFW knows how
> to execute the "get dram size" command it shall give the custom dram size.
> 
> - if the underlying FW does not report the dram size, we just proceed
> further and assign the default dram size.
> 
> Simplest way to address this is to remove amd_pmc_get_dram_size() function
> and directly call the "get dram size" command in the amd_pmc_s2d_init().
> 
> Reported-by: Mark Hasemeyer <markhas@chromium.org>
> Closes: https://lore.kernel.org/platform-driver-x86/3b224c62-a1d8-41bd-aced-5825f5f20e66@amd.com/
> Fixes: be8325fb3d8c ("platform/x86/amd: pmc: Get STB DRAM size from PMFW")
> Suggested-by: Sanket Goswami <Sanket.Goswami@amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> ---
> v4:
> - Based on review-ilpo branch (tip commit: 94ace9eda882)
> - Add Mark as "Reported-by:"
> - Add more commit log notes.

Thank, applied now to review-ilpo branch. I had to reflow your commit 
message because the lines were too long (try to remain within 72 
characters in the future). I also made other minor adjustments to the 
commit message.


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 i.