[PATCH v5] drm/i915/selftest/gsc: Ensure GSC Proxy init completes before selftests

[Ceraolo Spurio, Daniele]

On 7/12/2023 4:12 PM, Alan Previn wrote:
> On MTL, if the GSC Proxy init flows haven't completed, submissions to the
> GSC engine will fail. Those init flows are dependent on the mei's
> gsc_proxy component that is loaded in parallel with i915 and a
> worker that could potentially start after i915 driver init is done.
>
> That said, all subsytems that access the GSC engine today does check
> for such init flow completion before using the GSC engine. However,
> selftests currently don't wait on anything before starting.
>
> To fix this, add a waiter function at the start of __run_selftests
> that waits for gsc-proxy init flows to complete.
>
> Difference from prior versions:
>     v5: - Move the call to __wait_gsc_proxy_completed from common
>           __run_selftests dispatcher to the group-level selftest
>           function (Trvtko).
>         - change the pr_info to pr_warn if we hit the timeout.
>     v4: - Remove generalized waiters function table framework (Tvrtko).
>         - Remove mention of CI-framework-timeout from comments (Tvrtko).
>     v3: - Rebase to latest drm-tip.
>     v2: - Based on internal testing, increase the timeout for gsc-proxy
>           specific case to 8 seconds.
>
> Signed-off-by: Alan Previn <alan.previn.teres.alexis at intel.com>
> ---
>   .../gpu/drm/i915/selftests/i915_selftest.c    | 26 +++++++++++++++++++
>   1 file changed, 26 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_selftest.c b/drivers/gpu/drm/i915/selftests/i915_selftest.c
> index 39da0fb0d6d2..b03d03eac3d6 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_selftest.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_selftest.c
> @@ -24,6 +24,8 @@
>   #include <linux/random.h>
>   
>   #include "gt/intel_gt_pm.h"
> +#include "gt/uc/intel_gsc_fw.h"
> +
>   #include "i915_driver.h"
>   #include "i915_drv.h"
>   #include "i915_selftest.h"
> @@ -127,6 +129,26 @@ static void set_default_test_all(struct selftest *st, unsigned int count)
>   		st[i].enabled = true;
>   }
>   
> +static void
> +__wait_gsc_proxy_completed(struct drm_i915_private *i915)
> +{
> +	bool need_to_wait = (IS_ENABLED(CONFIG_INTEL_MEI_GSC_PROXY) &&
> +			     i915->media_gt &&
> +			     HAS_ENGINE(i915->media_gt, GSC0) &&
> +			     intel_uc_fw_is_loadable(&i915->media_gt->uc.gsc.fw));
> +	/*
> +	 * The gsc proxy component depends on the kernel component driver load ordering
> +	 * and in corner cases (the first time after an IFWI flash), init-completion
> +	 * firmware flows take longer.
> +	 */
> +	unsigned long timeout_ms = 8000;
> +
> +	if (need_to_wait &&
> +	    (wait_for(intel_gsc_uc_fw_proxy_init_done(&i915->media_gt->uc.gsc, true),

Small issue here: if proxy init fails, intel_gsc_uc_fw_proxy_init_done 
will keep returning false, so we'll wait for the full 8 secs. Maybe we 
can instead have a proxy_init_status function to differentiate between 
pending/failed/done. This would basically be a generalization of the 
checks you already have in https://patchwork.freedesktop.org/series/118723/.
Patch LGTM apart from this.

Daniele

> +	    timeout_ms)))
> +		pr_warn(DRIVER_NAME "Timed out waiting for gsc_proxy_completion!\n");
> +}
> +
>   static int __run_selftests(const char *name,
>   			   struct selftest *st,
>   			   unsigned int count,
> @@ -206,6 +228,8 @@ int i915_live_selftests(struct pci_dev *pdev)
>   	if (!i915_selftest.live)
>   		return 0;
>   
> +	__wait_gsc_proxy_completed(pdev_to_i915(pdev));
> +
>   	err = run_selftests(live, pdev_to_i915(pdev));
>   	if (err) {
>   		i915_selftest.live = err;
> @@ -227,6 +251,8 @@ int i915_perf_selftests(struct pci_dev *pdev)
>   	if (!i915_selftest.perf)
>   		return 0;
>   
> +	__wait_gsc_proxy_completed(pdev_to_i915(pdev));
> +
>   	err = run_selftests(perf, pdev_to_i915(pdev));
>   	if (err) {
>   		i915_selftest.perf = err;
>
> base-commit: 57ea1a97c50c63c77e3bfa46ee486e8a451be5e7