Re: [PATCH] platform/x86/amd: pmc: Use release_mem_region() to undo request_mem_region_muxed()

[Andy Shevchenko <andy@kernel.org>]

On Tue, Jul 11, 2023 at 11:59:20AM +0200, Hans de Goede wrote:
> Muxed (mem) regions will wait in request_mem_region_muxed() if the region
> is busy (in use by another consumer) during the call.
> 
> In order to wake-up possibly waiting other consumers of the region,
> it must be released by a release_mem_region() call, which will actually
> wake up any waiters.
> 
> release_mem_region() also frees the resource created by
> request_mem_region_muxed(), avoiding the need for the unmatched kfree().

Seems reasonable to me.
Do we need to have a Fixes tag?
Reviewed-by: Andy Shevchenko <andy@kernel.org>

> Cc: Mario Limonciello <mario.limonciello@amd.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Mario, can you ask one of the reporters with a machine which needs the quirk
> to test this ?
> ---
>  drivers/platform/x86/amd/pmc-quirks.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/platform/x86/amd/pmc-quirks.c b/drivers/platform/x86/amd/pmc-quirks.c
> index 362e7c0097d7..ad702463a65d 100644
> --- a/drivers/platform/x86/amd/pmc-quirks.c
> +++ b/drivers/platform/x86/amd/pmc-quirks.c
> @@ -11,7 +11,6 @@
>  #include <linux/dmi.h>
>  #include <linux/io.h>
>  #include <linux/ioport.h>
> -#include <linux/slab.h>
>  
>  #include "pmc.h"
>  
> @@ -135,12 +134,10 @@ static const struct dmi_system_id fwbug_list[] = {
>   */
>  static void amd_pmc_skip_nvme_smi_handler(u32 s2idle_bug_mmio)
>  {
> -	struct resource *res;
>  	void __iomem *addr;
>  	u8 val;
>  
> -	res = request_mem_region_muxed(s2idle_bug_mmio, 1, "amd_pmc_pm80");
> -	if (!res)
> +	if (!request_mem_region_muxed(s2idle_bug_mmio, 1, "amd_pmc_pm80"))
>  		return;
>  
>  	addr = ioremap(s2idle_bug_mmio, 1);
> @@ -152,8 +149,7 @@ static void amd_pmc_skip_nvme_smi_handler(u32 s2idle_bug_mmio)
>  
>  	iounmap(addr);
>  cleanup_resource:
> -	release_resource(res);
> -	kfree(res);
> +	release_mem_region(s2idle_bug_mmio, 1);
>  }
>  
>  void amd_pmc_process_restore_quirks(struct amd_pmc_dev *dev)
> -- 
> 2.41.0
> 

-- 
With Best Regards,
Andy Shevchenko