Re: [PATCH] media: venus: firmware: Use of_reserved_mem_lookup()

[Konrad Dybcio]

On 29.05.2023 20:16, Stephan Gerhold wrote:
> Reserved memory can be either looked up using the generic function
> of_address_to_resource() or using the special of_reserved_mem_lookup().
> The latter has the advantage that it ensures that the referenced memory
> region was really reserved and is not e.g. status = "disabled".
> 
> of_reserved_mem also supports allocating reserved memory dynamically at
> boot time. This works only when using of_reserved_mem_lookup() since
> there won't be a fixed address in the device tree.
> 
> Switch the code to use of_reserved_mem_lookup(). There is no functional
> difference for static reserved memory allocations.
> 
> Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
> ---
> See e.g. [1] for an example of dynamically allocated reserved memory.
> (This patch does *not* depend on [1] and is useful without as well...)
> 
> [1]: https://lore.kernel.org/linux-arm-msm/20230510-dt-resv-bottom-up-v1-5-3bf68873dbed@xxxxxxxxxxx/
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>

>  drivers/media/platform/qcom/venus/firmware.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
[...]

> -	mem_va = memremap(r.start, *mem_size, MEMREMAP_WC);
> +	mem_va = memremap(*mem_phys, *mem_size, MEMREMAP_WC);
>  	if (!mem_va) {
> -		dev_err(dev, "unable to map memory region: %pR\n", &r);
> +		dev_err(dev, "unable to map memory region %pa size %#zx\n", mem_phys, *mem_size);
Nit : I'm not sure which is more useful, but many mapping functions
seem to prefer printing

start, start+size-1

instead of 

start, size

on failure.

Konrad
>  		ret = -ENOMEM;
>  		goto err_release_fw;
>  	}
> @@ -138,8 +142,6 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
>  	memunmap(mem_va);
>  err_release_fw:
>  	release_firmware(mdt);
> -err_put_node:
> -	of_node_put(node);
>  	return ret;
>  }
>  
> 
> ---
> base-commit: 9f9f8ca6f012d25428f8605cb36369a449db8508
> change-id: 20230529-venus-of-rmem-f649885114fd
> 
> Best regards,