Re: [PATCH v5 2/5] media: iris: scale MMCX power domain on SM8250

[Bryan O'Donoghue <bod@kernel.org>]

On 09/02/2026 01:32, Dmitry Baryshkov wrote:
> On SM8250 most of the video clocks are powered by the MMCX domain, while
> the PLL is powered on by the MX domain. Extend the driver to support
> scaling both power domains, while keeping compatibility with the
> existing DTs, which define only the MX domain.
> 
> Fixes: 79865252acb6 ("media: iris: enable video driver probe of SM8250 SoC")
> Reviewed-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
>   drivers/media/platform/qcom/iris/iris_platform_gen1.c | 2 +-
>   drivers/media/platform/qcom/iris/iris_probe.c         | 7 +++++++
>   2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/qcom/iris/iris_platform_gen1.c b/drivers/media/platform/qcom/iris/iris_platform_gen1.c
> index df8e6bf9430e..aa71f7f53ee3 100644
> --- a/drivers/media/platform/qcom/iris/iris_platform_gen1.c
> +++ b/drivers/media/platform/qcom/iris/iris_platform_gen1.c
> @@ -281,7 +281,7 @@ static const struct bw_info sm8250_bw_table_dec[] = {
> 
>   static const char * const sm8250_pmdomain_table[] = { "venus", "vcodec0" };
> 
> -static const char * const sm8250_opp_pd_table[] = { "mx" };
> +static const char * const sm8250_opp_pd_table[] = { "mx", "mmcx" };
> 
>   static const struct platform_clk_data sm8250_clk_table[] = {
>   	{IRIS_AXI_CLK,  "iface"        },
> diff --git a/drivers/media/platform/qcom/iris/iris_probe.c b/drivers/media/platform/qcom/iris/iris_probe.c
> index 7b612ad37e4f..74ec81e3d622 100644
> --- a/drivers/media/platform/qcom/iris/iris_probe.c
> +++ b/drivers/media/platform/qcom/iris/iris_probe.c
> @@ -64,6 +64,13 @@ static int iris_init_power_domains(struct iris_core *core)
>   		return ret;
> 
>   	ret =  devm_pm_domain_attach_list(core->dev, &iris_opp_pd_data, &core->opp_pmdomain_tbl);
> +	/* backwards compatibility for incomplete ABI SM8250 */
> +	if (ret == -ENODEV &&
> +	    of_device_is_compatible(core->dev->of_node, "qcom,sm8250-venus")) {
> +		iris_opp_pd_data.num_pd_names--;
> +		ret = devm_pm_domain_attach_list(core->dev, &iris_opp_pd_data,


ci is choking on this.

=>

drivers/media/platform/qcom/venus/pm_helpers.c: In function 
‘vcodec_domains_get’:
drivers/media/platform/qcom/venus/pm_helpers.c:910:41: error: decrement 
of read-only member ‘num_pd_names’
   910 |                 opp_pd_data.num_pd_names--;
       |                                         ^~

=>

include/linux/pm_domain.h

struct dev_pm_domain_attach_data {
         const char * const *pd_names;
         const u32 num_pd_names;
         const u32 pd_flags;
};

=>

struct dev_pm_domain_attach_data opp_pd_data = {
	.pd_names = res->opp_pmdomain,
	.num_pd_names = res->opp_pmdomain_num,
	.pd_flags = PD_FLAG_DEV_LINK_ON | PD_FLAG_REQUIRED_OPP,
};

---
bod