Re: [PATCH 1/2] platform/x86/amd/pmc: Fix fetching DRAM size mechanism

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

On Mon, 9 Oct 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.
> 
> Add a missing amd_pmc_get_smu_version() call to amd_pmc_get_dram_size().
> 
> 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>
> ---
> based on review-ilpo, can be added on top of recent stb changes
> 
>  drivers/platform/x86/amd/pmc/pmc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c
> index 1424c03c1f03..92adf4523736 100644
> --- a/drivers/platform/x86/amd/pmc/pmc.c
> +++ b/drivers/platform/x86/amd/pmc/pmc.c
> @@ -981,6 +981,10 @@ static int amd_pmc_get_dram_size(struct amd_pmc_dev *dev)
>  {
>  	int ret;
>  
> +	ret = amd_pmc_get_smu_version(dev);
> +	if (ret)
> +		return ret;
> +
>  	switch (dev->cpu_id) {
>  	case AMD_CPU_ID_YC:
>  		if (!(dev->major > 90 || (dev->major == 90 && dev->minor > 39))) {

Does this really belong here? Correct me if I recall wrong but the reason 
why amd_pmc_get_smu_version() was not always done during init was that it 
added noticeable delay to boot? Based on that, I kind of assumed it's 
generic thing (and a such, unrelated to amd_pmc_get_dram_size()) so why is 
this call this deep in the call chain? Perhaps amd_pmc_s2d_init() would 
be more appropriate place for it since you now make the call 
unconditional anyway for that code path?

-- 
 i.