linux-kernel - Re: [PATCH v2 20/20] media: venus: pm_helpers: Use reset

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Date: Wed, 14 Feb 2024 14:31:09 +0100
From: Philipp Zabel <p.zabel@...gutronix.de>
To: Konrad Dybcio <konrad.dybcio@...aro.org>, Stanimir Varbanov
 <stanimir.k.varbanov@...il.com>, Vikash Garodia
 <quic_vgarodia@...cinc.com>,  Bryan O'Donoghue
 <bryan.odonoghue@...aro.org>, Andy Gross <agross@...nel.org>, Bjorn
 Andersson <andersson@...nel.org>,  Mauro Carvalho Chehab
 <mchehab@...nel.org>, Dikshita Agarwal <quic_dikshita@...cinc.com>
Cc: Marijn Suijten <marijn.suijten@...ainline.org>, Stanimir Varbanov
	 <stanimir.varbanov@...aro.org>, Mauro Carvalho Chehab
	 <mchehab+huawei@...nel.org>, linux-media@...r.kernel.org, 
	linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 20/20] media: venus: pm_helpers: Use reset_bulk API

Hi Konrad,

On Fr, 2024-02-09 at 22:10 +0100, Konrad Dybcio wrote:
> All of the resets are toggled together. Use the bulk api to save on some
> code complexity.
> 
> The delay between resets is now correctly determined by the reset
> framework.

If this is a recent change, could you reference the commit?

> Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
> ---
>  drivers/media/platform/qcom/venus/core.c       | 15 ++++++++++-----
>  drivers/media/platform/qcom/venus/core.h       |  4 ++--
>  drivers/media/platform/qcom/venus/pm_helpers.c | 15 +++------------
>  3 files changed, 15 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
> index 873affe17537..ff5601a5ce77 100644
> --- a/drivers/media/platform/qcom/venus/core.c
> +++ b/drivers/media/platform/qcom/venus/core.c
> @@ -328,11 +328,16 @@ static int venus_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	for (i = 0; i < res->resets_num; i++) {
> -		core->resets[i] = devm_reset_control_get_exclusive(dev, res->resets[i]);
> -		if (IS_ERR(core->resets[i]))
> -			return PTR_ERR(core->resets[i]);
> -	}
> +	core->resets = devm_kcalloc(dev, res->resets_num, sizeof(*core->resets), GFP_KERNEL);

Since VIDC_RESETS_NUM_MAX is only 2, I don't think a separate
allocation is worth it.

> +	if (res->resets_num && !core->resets)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < res->resets_num; i++)
> +		core->resets[i].id = res->resets[i];
> +
> +	ret = devm_reset_control_bulk_get_exclusive(dev, res->resets_num, core->resets);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get resets\n");
>  
>  	ret = venus_get_resources(core);
>  	if (ret)
> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
> index 6ecaa3e38cac..2376b9cbdf2c 100644
> --- a/drivers/media/platform/qcom/venus/core.h
> +++ b/drivers/media/platform/qcom/venus/core.h
> @@ -130,7 +130,7 @@ struct venus_format {
>   * @pmdomains:	a pointer to a list of pmdomains
>   * @opp_dl_venus: an device-link for device OPP
>   * @opp_pmdomain: an OPP power-domain
> - * @resets: an array of reset signals
> + * @resets: a reset_control_bulk_data array of hardware reset signals
>   * @vdev_dec:	a reference to video device structure for decoder instances
>   * @vdev_enc:	a reference to video device structure for encoder instances
>   * @v4l2_dev:	a holder for v4l2 device structure
> @@ -183,7 +183,7 @@ struct venus_core {
>  	struct dev_pm_domain_list *pmdomains;
>  	struct device_link *opp_dl_venus;
>  	struct device *opp_pmdomain;
> -	struct reset_control *resets[VIDC_RESETS_NUM_MAX];
> +	struct reset_control_bulk_data *resets;

Any reason not to just keep this as an array[VIDC_RESETS_NUM_MAX]?

>  	struct video_device *vdev_dec;
>  	struct video_device *vdev_enc;
>  	struct v4l2_device v4l2_dev;
> diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
> index 9df8f2292c17..170fb131cb1e 100644
> --- a/drivers/media/platform/qcom/venus/pm_helpers.c
> +++ b/drivers/media/platform/qcom/venus/pm_helpers.c
> @@ -865,21 +865,12 @@ void vcodec_domains_put(struct venus_core *core)
>  static int core_resets_reset(struct venus_core *core)
>  {
>  	const struct venus_resources *res = core->res;
> -	unsigned int i;
>  	int ret;
>  
> -	for (i = 0; i < res->resets_num; i++) {
> -		ret = reset_control_assert(core->resets[i]);
> -		if (ret)
> -			goto err;
> -
> -		usleep_range(150, 250);
> -		ret = reset_control_deassert(core->resets[i]);
> -		if (ret)
> -			goto err;
> -	}
> +	ret = reset_control_bulk_reset(res->resets_num, core->resets);
> +	if (ret)
> +		dev_err(core->dev, "Failed to toggle resets: %d\n", ret);
>  
> -err:
>  	return ret;

Could be simplified to:

	return reset_control_bulk_reset(res->resets_num, core-
>resets);

regards
Philipp