Re: [PATCH v4 01/11] platform/x86/amd/pmc: Move STB block into amd_pmc_s2d_init()

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

On Thu, 7 Nov 2024, Shyam Sundar S K wrote:

> Transfer the support for STB-related file operations to the
> amd_pmc_s2d_init() function, thereby consolidating the STB and S2D
> (Spill to DRAM) functionality in one location.
> 
> For older platforms that supported S2D, exit immediately after creating
> debugfs. These platforms may not support the PMFW messages available on
> newer platforms. This adjustment is necessary due to the relocation of
> debugfs creation into amd_pmc_s2d_init().
> 
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
> Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> ---
>  drivers/platform/x86/amd/pmc/pmc.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c
> index bbb8edb62e00..54ceb2f9bf56 100644
> --- a/drivers/platform/x86/amd/pmc/pmc.c
> +++ b/drivers/platform/x86/amd/pmc/pmc.c
> @@ -648,15 +648,6 @@ static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
>  			    &s0ix_stats_fops);
>  	debugfs_create_file("amd_pmc_idlemask", 0644, dev->dbgfs_dir, dev,
>  			    &amd_pmc_idlemask_fops);
> -	/* Enable STB only when the module_param is set */
> -	if (enable_stb) {
> -		if (amd_pmc_is_stb_supported(dev))
> -			debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
> -					    &amd_pmc_stb_debugfs_fops_v2);
> -		else
> -			debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
> -					    &amd_pmc_stb_debugfs_fops);
> -	}
>  }
>  
>  static void amd_pmc_dump_registers(struct amd_pmc_dev *dev)
> @@ -982,6 +973,15 @@ static int amd_pmc_s2d_init(struct amd_pmc_dev *dev)
>  	u32 size = 0;
>  	int ret;
>  
> +	if (amd_pmc_is_stb_supported(dev)) {
> +		debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
> +				    &amd_pmc_stb_debugfs_fops_v2);
> +	} else {
> +		debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
> +				    &amd_pmc_stb_debugfs_fops);
> +		return 0;
> +	}
> +
>  	/* Spill to DRAM feature uses separate SMU message port */
>  	dev->msg_port = 1;

This now runs afoul the other issue you even mentioned yourself (IIRC), 
that is, dev->dbgfs_dir is initialized inside amd_pmc_dbgfs_register() 
which is only called after amd_pmc_s2d_init() until it is moved in patch 
2.

Thus, you need to combine patches 1 & 2 so you don't get a broken kernel
after this patch.

Please also move the enable_stb check inside amd_pmc_s2d_init() in this 
patch since that's another thing you've now broken in between patches 1 & 
3.

So to reiterate, in the first patch combine: Patch 1 + 2 + the if () logic 
move from amd_pmc_probe() into amd_pmc_s2d_init().

-- 
 i.