Re: [PATCH v3 12/17] media: venus: core: Add support for opp tables/perf voting

Stanimir Varbanov
2020-04-29T14:36:27Z

Hi Rajendra,

Thanks for the patch!

On 4/28/20 4:33 PM, Rajendra Nayak wrote:
> Add support to add OPP tables and perf voting on the OPP powerdomain.
> This is needed so venus votes on the corresponding performance state
> for the OPP powerdomain along with setting the core clock rate.
>
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> Cc: Stanimir Varbanov <stanimir.varbanov@linaro.org>
> Cc: linux-media@vger.kernel.org
> ---
> drivers/media/platform/qcom/venus/core.c | 28 +++++++++++++++++++
> drivers/media/platform/qcom/venus/core.h | 5 ++++
> drivers/media/platform/qcom/venus/pm_helpers.c | 37 +++++++++++++++++++++++---
> 3 files changed, 66 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
> index 194b10b9..e98fea92 100644
> --- a/drivers/media/platform/qcom/venus/core.c
> +++ b/drivers/media/platform/qcom/venus/core.c
> @@ -12,6 +12,7 @@
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> #include <linux/types.h>
> +#include <linux/pm_opp.h>
> #include <linux/pm_runtime.h>
> #include <media/videobuf2-v4l2.h>
> #include <media/v4l2-mem2mem.h>
> @@ -214,6 +215,20 @@ static int venus_probe(struct platform_device *pdev)
> if (!core->pm_ops)
> return -ENODEV;
>
> + core->opp_table = dev_pm_opp_set_clkname(dev, "core");

Should we set opp clkname if opp_of_add_table fails? We have platforms
which don't have opp tables in Venus DT node. We have to be backward
compatible for them.

> + if (IS_ERR(core->opp_table))
> + return PTR_ERR(core->opp_table);
> +
> + if (core->res->opp_pmdomain) {
> + ret = dev_pm_opp_of_add_table(dev);
> + if (!ret) {
> + core->has_opp_table = true;
> + } else if (ret != -ENODEV) {

Is it possible dev_pm_opp_of_add_table() to return EPROBE_DEFER?

> + dev_err(dev, "Invalid OPP table in Device tree\n");

... if so, please drop dev_err.

> + return ret;
> + }
> + }
> +
> if (core->pm_ops->core_get) {
> ret = core->pm_ops->core_get(dev);
> if (ret)
> @@ -301,6 +316,9 @@ static int venus_probe(struct platform_device *pdev)
> err_venus_shutdown:
> venus_shutdown(core);
> err_runtime_disable:
> + if (core->res->opp_pmdomain && core->has_opp_table)
> + dev_pm_opp_of_remove_table(dev);
> + dev_pm_opp_put_clkname(core->opp_table);
> pm_runtime_set_suspended(dev);
> pm_runtime_disable(dev);
> hfi_destroy(core);
> @@ -326,6 +344,10 @@ static int venus_remove(struct platform_device *pdev)
>
> venus_firmware_deinit(core);
>
> + if (core->res->opp_pmdomain && core->has_opp_table)
> + dev_pm_opp_of_remove_table(dev);
> + dev_pm_opp_put_clkname(core->opp_table);
> +
> pm_runtime_put_sync(dev);
> pm_runtime_disable(dev);
>
> @@ -350,6 +372,10 @@ static __maybe_unused int venus_runtime_suspend(struct device *dev)
> if (ret)
> return ret;
>
> + /* Drop the performance state vote */
> + if (core->opp_pmdomain)
> + dev_pm_opp_set_rate(dev, 0);
> +
> if (pm_ops->core_power)
> ret = pm_ops->core_power(dev, POWER_OFF);
>
> @@ -511,6 +537,7 @@ static const struct venus_resources sdm845_res_v2 = {
> .vcodec_clks_num = 2,
> .vcodec_pmdomains = { "venus", "vcodec0", "vcodec1" },
> .vcodec_pmdomains_num = 3,
> + .opp_pmdomain = (const char *[]) { "opp-pd", NULL },
> .vcodec_num = 2,
> .max_load = 3110400, /* 4096x2160@90 */
> .hfi_version = HFI_VERSION_4XX,
> @@ -556,6 +583,7 @@ static const struct venus_resources sc7180_res = {
> .vcodec_clks_num = 2,
> .vcodec_pmdomains = { "venus", "vcodec0" },
> .vcodec_pmdomains_num = 2,
> + .opp_pmdomain = (const char *[]) { "opp-pd", NULL },
> .vcodec_num = 1,
> .hfi_version = HFI_VERSION_4XX,
> .vmem_id = VIDC_RESOURCE_NONE,
> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
> index bd3ac6a..cc1d511 100644
> --- a/drivers/media/platform/qcom/venus/core.h
> +++ b/drivers/media/platform/qcom/venus/core.h
> @@ -62,6 +62,7 @@ struct venus_resources {
> unsigned int vcodec_clks_num;
> const char * const vcodec_pmdomains[VIDC_PMDOMAINS_NUM_MAX];
> unsigned int vcodec_pmdomains_num;
> + const char **opp_pmdomain;
> unsigned int vcodec_num;
> enum hfi_version hfi_version;
> u32 max_load;
> @@ -144,8 +145,12 @@ struct venus_core {
> struct clk *vcodec1_clks[VIDC_VCODEC_CLKS_NUM_MAX];
> struct icc_path *video_path;
> struct icc_path *cpucfg_path;
> + struct opp_table *opp_table;
> + bool has_opp_table;
> struct device_link *pd_dl_venus;
> struct device *pmdomains[VIDC_PMDOMAINS_NUM_MAX];
> + struct device_link *opp_dl_venus;
> + struct device *opp_pmdomain;
> 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 abf9315..bc5bbd2 100644
> --- a/drivers/media/platform/qcom/venus/pm_helpers.c
> +++ b/drivers/media/platform/qcom/venus/pm_helpers.c
> @@ -9,6 +9,7 @@
> #include <linux/iopoll.h>
> #include <linux/kernel.h>
> #include <linux/pm_domain.h>
> +#include <linux/pm_opp.h>
> #include <linux/pm_runtime.h>
> #include <linux/types.h>
> #include <media/v4l2-mem2mem.h>
> @@ -66,10 +67,9 @@ static void core_clks_disable(struct venus_core *core)
>
> static int core_clks_set_rate(struct venus_core *core, unsigned long freq)
> {
> - struct clk *clk = core->clks[0];
> int ret;
>
> - ret = clk_set_rate(clk, freq);
> + ret = dev_pm_opp_set_rate(core->dev, freq);

Is this will work for legacy platforms without OPP tables?

Also what about the other clocks (vicodec0,1) in this function.

> if (ret)
> return ret;
>
> @@ -740,13 +740,15 @@ static int venc_power_v4(struct device *dev, int on)
>
> static int vcodec_domains_get(struct device *dev)
> {
> + struct opp_table *opp_table;
> + struct device **opp_virt_dev;
> struct venus_core *core = dev_get_drvdata(dev);
> const struct venus_resources *res = core->res;
> struct device *pd;
> unsigned int i;
>
> if (!res->vcodec_pmdomains_num)
> - return -ENODEV;
> + goto skip_pmdomains;
>
> for (i = 0; i < res->vcodec_pmdomains_num; i++) {
> pd = dev_pm_domain_attach_by_name(dev,
> @@ -763,6 +765,24 @@ static int vcodec_domains_get(struct device *dev)
> if (!core->pd_dl_venus)
> return -ENODEV;
>
> +skip_pmdomains:
> + if (!res->opp_pmdomain || !core->has_opp_table)
> + return 0;
> +
> + /* Attach the power domain for setting performance state */
> + opp_table = dev_pm_opp_attach_genpd(dev, res->opp_pmdomain, &opp_virt_dev);
> + if (IS_ERR(opp_table)) {
> + return PTR_ERR(opp_table);
> + } else if (opp_virt_dev) {
> + core->opp_pmdomain = *opp_virt_dev;
> + core->opp_dl_venus = device_link_add(dev, core->opp_pmdomain,
> + DL_FLAG_RPM_ACTIVE |
> + DL_FLAG_PM_RUNTIME |
> + DL_FLAG_STATELESS);
> + if (!core->opp_dl_venus)
> + return -ENODEV;

I think as you return ENODEV you have to detach opp domain here because
vcodec_domains_put() is not called in error path.

> + }
> +
> return 0;
> }
>
> @@ -773,7 +793,7 @@ static void vcodec_domains_put(struct device *dev)
> unsigned int i;
>
> if (!res->vcodec_pmdomains_num)
> - return;
> + goto skip_pmdomains;
>
> if (core->pd_dl_venus)
> device_link_del(core->pd_dl_venus);
> @@ -783,6 +803,15 @@ static void vcodec_domains_put(struct device *dev)
> continue;
> dev_pm_domain_detach(core->pmdomains[i], true);
> }
> +
> +skip_pmdomains:
> + if (!res->opp_pmdomain)
> + return;
> +
> + if (core->opp_dl_venus)
> + device_link_del(core->opp_dl_venus);
> +
> + dev_pm_domain_detach(core->opp_pmdomain, true);
> }
>
> static int core_get_v4(struct device *dev)
>

--
regards,
Stan