Re: [PATCH 3/9] soundwire: amd: allocate sdw_amd_ctx pdev array dynamically

[Mukunda,Vijendar]

On 03/10/26 13:22, Vinod Koul wrote:
> On 17-09-26, 14:32, Vijendar Mukunda wrote:
>> Replace the fixed-size pdev[AMD_ACP63_SDW_MAX_MANAGER_COUNT] member of
>> struct sdw_amd_ctx with a dynamically allocated pointer array. The array
>> is sized by max_manager_count via kcalloc() in sdw_amd_probe_controller()
>> and freed on all error paths and in sdw_amd_cleanup().
>>
>> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@xxxxxxx>
>> ---
>>  drivers/soundwire/amd_init.c      | 12 ++++++++++++
>>  include/linux/soundwire/sdw_amd.h |  2 +-
>>  2 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/soundwire/amd_init.c b/drivers/soundwire/amd_init.c
>> index 15d117172bdb..94d766b3f8af 100644
>> --- a/drivers/soundwire/amd_init.c
>> +++ b/drivers/soundwire/amd_init.c
>> @@ -62,6 +62,7 @@ static int sdw_amd_cleanup(struct sdw_amd_ctx *ctx)
>>  			continue;
>>  		platform_device_unregister(ctx->pdev[i]);
>>  	}
>> +	kfree(ctx->pdev);
>>  
>>  	return 0;
>>  }
>> @@ -116,8 +117,16 @@ static struct sdw_amd_ctx *sdw_amd_probe_controller(struct sdw_amd_res *res)
>>  
>>  	ctx->count = count;
>>  	ctx->link_mask = res->link_mask;
>> +
>> +	ctx->pdev = kcalloc(max_manager_count, sizeof(*ctx->pdev), GFP_KERNEL);
> why not use managed api for this?
The reason devm_kcalloc() cannot be used here is that
sdw_amd_cleanup() explicitly frees ctx->pdev using kfree().
 
If devm_kcalloc(res->parent, ...) were used, the allocation
would also be tracked by devres and freed automatically during
device unbind, resulting in a double-free.
 
Therefore, the existing manual alloc/free lifecycle is
intentional.

>> +	if (!ctx->pdev) {
>> +		kfree(ctx);
>> +		return NULL;
>> +	}
>> +
>>  	struct resource *sdw_res __free(kfree) = kzalloc_obj(*sdw_res);
>>  	if (!sdw_res) {
>> +		kfree(ctx->pdev);
>>  		kfree(ctx);
>>  		return NULL;
>>  	}
>> @@ -127,6 +136,7 @@ static struct sdw_amd_ctx *sdw_amd_probe_controller(struct sdw_amd_res *res)
>>  
>>  	sdw_pdata = kcalloc(max_manager_count, sizeof(*sdw_pdata), GFP_KERNEL);
>>  	if (!sdw_pdata) {
>> +		kfree(ctx->pdev);
>>  		kfree(ctx);
>>  		return NULL;
>>  	}
>> @@ -134,6 +144,7 @@ static struct sdw_amd_ctx *sdw_amd_probe_controller(struct sdw_amd_res *res)
>>  	pdevinfo = kcalloc(max_manager_count, sizeof(*pdevinfo), GFP_KERNEL);
>>  	if (!pdevinfo) {
>>  		kfree(sdw_pdata);
>> +		kfree(ctx->pdev);
>>  		kfree(ctx);
>>  		return NULL;
>>  	}
>> @@ -171,6 +182,7 @@ static struct sdw_amd_ctx *sdw_amd_probe_controller(struct sdw_amd_res *res)
>>  
>>  	kfree(pdevinfo);
>>  	kfree(sdw_pdata);
>> +	kfree(ctx->pdev);
>>  	kfree(ctx);
>>  	return NULL;
>>  }
>> diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
>> index 40ba84c3b2cc..476de2c30389 100644
>> --- a/include/linux/soundwire/sdw_amd.h
>> +++ b/include/linux/soundwire/sdw_amd.h
>> @@ -139,7 +139,7 @@ struct sdw_amd_acpi_info {
>>  struct sdw_amd_ctx {
>>  	int count;
>>  	u32 link_mask;
>> -	struct platform_device *pdev[AMD_ACP63_SDW_MAX_MANAGER_COUNT];
>> +	struct platform_device **pdev;
>>  	struct sdw_peripherals *peripherals;
>>  };
>>  
>> -- 
>> 2.48.1