On Fri, 10 Jun 2022 16:47:12 -0700, Vinay Belgaumkar wrote:
>
> This test will validate we can achieve actual frequency of RP0. Pcode
> grants frequencies based on what GuC is requesting. However, thermal
> throttling can limit what is being granted. Add a test to request for
> max, but don't fail the test if RP0 is not granted due to throttle
> reasons.
>
> Also optimize the selftest by using a common run_test function to avoid
> code duplication.
The refactoring does change the order of operations (changing the freq vs
spawning the spinner) but should be fine I think.
> Rename the "clamp" tests to vary_max_freq and vary_min_freq.
Either is ok, but maybe "clamp" names were ok I think since they verify req
freq is clamped at min/max.
>
> v2: Fix compile warning
>
> Fixes 8ee2c227822e ("drm/i915/guc/slpc: Add SLPC selftest")
> Signed-off-by: Vinay Belgaumkar <vinay.belgaum...@intel.com>
> ---
> drivers/gpu/drm/i915/gt/selftest_slpc.c | 323 ++++++++++++------------
> 1 file changed, 158 insertions(+), 165 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/selftest_slpc.c
> b/drivers/gpu/drm/i915/gt/selftest_slpc.c
> index b768cea5943d..099129aae9a5 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_slpc.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_slpc.c
> @@ -8,6 +8,11 @@
> #define delay_for_h2g() usleep_range(H2G_DELAY, H2G_DELAY + 10000)
> #define FREQUENCY_REQ_UNIT DIV_ROUND_CLOSEST(GT_FREQUENCY_MULTIPLIER, \
> GEN9_FREQ_SCALER)
> +enum test_type {
> + VARY_MIN,
> + VARY_MAX,
> + MAX_GRANTED
> +};
>
> static int slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 freq)
> {
> @@ -36,147 +41,120 @@ static int slpc_set_max_freq(struct intel_guc_slpc
> *slpc, u32 freq)
> return ret;
> }
>
> -static int live_slpc_clamp_min(void *arg)
> +static int vary_max_freq(struct intel_guc_slpc *slpc, struct intel_rps *rps,
> + u32 *max_act_freq)
Please run checkpatch, indentation seems off.
> {
> - struct drm_i915_private *i915 = arg;
> - struct intel_gt *gt = to_gt(i915);
> - struct intel_guc_slpc *slpc = >->uc.guc.slpc;
> - struct intel_rps *rps = >->rps;
> - struct intel_engine_cs *engine;
> - enum intel_engine_id id;
> - struct igt_spinner spin;
> + u32 step, max_freq, req_freq;
> + u32 act_freq;
> u32 slpc_min_freq, slpc_max_freq;
> int err = 0;
>
> - if (!intel_uc_uses_guc_slpc(>->uc))
> - return 0;
> -
> - if (igt_spinner_init(&spin, gt))
> - return -ENOMEM;
> + slpc_min_freq = slpc->min_freq;
> + slpc_max_freq = slpc->rp0_freq;
nit but we don't really need such variables since we don't change their
values, we should just use slpc->min_freq, slpc->rp0_freq directly. I'd
change this in all places in this patch.
>
> - if (intel_guc_slpc_get_max_freq(slpc, &slpc_max_freq)) {
> - pr_err("Could not get SLPC max freq\n");
> - return -EIO;
> - }
> -
> - if (intel_guc_slpc_get_min_freq(slpc, &slpc_min_freq)) {
> - pr_err("Could not get SLPC min freq\n");
> - return -EIO;
Why do we need these two function calls? Can't we just use slpc->rp0_freq
and slpc->min_freq as we are doing in the vary_min/max_freq() functions
above?
Also, as mentioned below I think here we should just do:
slpc_set_max_freq(slpc, slpc->rp0_freq);
slpc_set_min_freq(slpc, slpc->min_freq);
to restore freq to a known state before starting the test (just in case a
previous test changed the values).
> - }
> -
> - if (slpc_min_freq == slpc_max_freq) {
> - pr_err("Min/Max are fused to the same value\n");
> - return -EINVAL;
What if they are actually equal? I think basically the max/min freq test
loops will just not be entered (so effectively the tests will just
skip). The granted freq test will be fine. So I think we can just delete
this if statement?
(It is showing deleted above in the patch but is in the new code somewhere
too).
> - }
> -
> - intel_gt_pm_wait_for_idle(gt);
> - intel_gt_pm_get(gt);
> - for_each_engine(engine, gt, id) {
> - struct i915_request *rq;
> - u32 step, min_freq, req_freq;
> - u32 act_freq, max_act_freq;
> -
> - if (!intel_engine_can_store_dword(engine))
> - continue;
> + /* Go from max to min in 5 steps */
> + step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
> + *max_act_freq = slpc_min_freq;
> + for (max_freq = slpc_max_freq; max_freq > slpc_min_freq;
> + max_freq -= step) {
> + err = slpc_set_max_freq(slpc, max_freq);
> + if (err)
> + break;
>
> - /* Go from min to max in 5 steps */
> - step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
> - max_act_freq = slpc_min_freq;
> - for (min_freq = slpc_min_freq; min_freq < slpc_max_freq;
> - min_freq += step) {
> - err = slpc_set_min_freq(slpc, min_freq);
> - if (err)
> - break;
> -
> - st_engine_heartbeat_disable(engine);
> -
> - rq = igt_spinner_create_request(&spin,
> - engine->kernel_context,
> - MI_NOOP);
> - if (IS_ERR(rq)) {
> - err = PTR_ERR(rq);
> - st_engine_heartbeat_enable(engine);
> - break;
> - }
> + req_freq = intel_rps_read_punit_req_frequency(rps);
>
> - i915_request_add(rq);
> + /* GuC requests freq in multiples of 50/3 MHz */
> + if (req_freq > (max_freq + FREQUENCY_REQ_UNIT)) {
> + pr_err("SWReq is %d, should be at most %d\n", req_freq,
> + max_freq + FREQUENCY_REQ_UNIT);
> + err = -EINVAL;
Probably a nit but check can be (so should we be checking both high and low
limits?):
if (req_freq > (max_freq + FREQUENCY_REQ_UNIT) ||
req_freq < (slpc_min_freq - FREQUENCY_REQ_UNIT))
Though if we do this we'd need to change the pr_err() or have two separate
if statements. Not sure if it's worth it but thought I'll mention it.
> +static int vary_min_freq(struct intel_guc_slpc *slpc, struct intel_rps *rps,
> + u32 *max_act_freq)
> +{
> + u32 step, min_freq, req_freq;
> + u32 act_freq;
> + u32 slpc_min_freq, slpc_max_freq;
> + int err = 0;
>
> - act_freq = intel_rps_read_actual_frequency(rps);
> - if (act_freq > max_act_freq)
> - max_act_freq = act_freq;
> + slpc_min_freq = slpc->min_freq;
> + slpc_max_freq = slpc->rp0_freq;
>
> - igt_spinner_end(&spin);
> - st_engine_heartbeat_enable(engine);
> - }
> + /* Go from min to max in 5 steps */
> + step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
> + *max_act_freq = slpc_min_freq;
> + for (min_freq = slpc_min_freq; min_freq < slpc_max_freq;
> + min_freq += step) {
> + err = slpc_set_min_freq(slpc, min_freq);
> + if (err)
> + break;
>
> - pr_info("Max actual frequency for %s was %d\n",
> - engine->name, max_act_freq);
> + req_freq = intel_rps_read_punit_req_frequency(rps);
>
> - /* Actual frequency should rise above min */
> - if (max_act_freq == slpc_min_freq) {
Nit again. This check is somewhere in the new code but I think a better
check is
if (max_act_freq <= slpc_min_freq)
just in case the act freq for whatever reason falls below
slpc_min_freq. Even if we know this is impossible (bugs make the impossible
possible).
> - pr_err("Actual freq did not rise above min\n");
> + /* GuC requests freq in multiples of 50/3 MHz */
> + if (req_freq < (min_freq - FREQUENCY_REQ_UNIT)) {
> + pr_err("SWReq is %d, should be at least %d\n", req_freq,
> + min_freq - FREQUENCY_REQ_UNIT);
> err = -EINVAL;
Again nit as above, but check can be:
if (req_freq < (min_freq - FREQUENCY_REQ_UNIT) ||
req_freq > (slpc_max_freq + FREQUENCY_REQ_UNIT)) {
> }
>
> + act_freq = intel_rps_read_actual_frequency(rps);
> + if (act_freq > *max_act_freq)
> + *max_act_freq = act_freq;
> +
> if (err)
> break;
> }
>
> - /* Restore min/max frequencies */
> - slpc_set_max_freq(slpc, slpc_max_freq);
> - slpc_set_min_freq(slpc, slpc_min_freq);
> + return err;
> +}
>
> - if (igt_flush_test(gt->i915))
> - err = -EIO;
> +static int max_granted_freq(struct intel_guc_slpc *slpc, struct intel_rps
> *rps, u32 *max_act_freq)
> +{
> + struct intel_gt *gt = rps_to_gt(rps);
> + u32 perf_limit_reasons;
> + int err = 0;
>
> - intel_gt_pm_put(gt);
> - igt_spinner_fini(&spin);
> - intel_gt_pm_wait_for_idle(gt);
> + err = slpc_set_min_freq(slpc, slpc->rp0_freq);
> + if (err)
> + return err;
> +
> + *max_act_freq = intel_rps_read_actual_frequency(rps);
> + if (!(*max_act_freq == slpc->rp0_freq)) {
> + /* Check if there was some throttling by pcode */
> + perf_limit_reasons = intel_uncore_read(gt->uncore,
> GT0_PERF_LIMIT_REASONS);
> +
> + /* If not, this is an error */
> + if (perf_limit_reasons && GT0_PERF_LIMIT_REASONS_MASK) {
> + pr_err("Pcode did not grant max freq\n");
> + err = -EINVAL;
Looks incorrect, probably something like:
if (!(perf_limit_reasons & GT0_PERF_LIMIT_REASONS_MASK))
> + }
> + }
>
> return err;
> }
>
> -static int live_slpc_clamp_max(void *arg)
> +static int run_test(struct intel_gt *gt, int test_type)
> {
> - struct drm_i915_private *i915 = arg;
> - struct intel_gt *gt = to_gt(i915);
> - struct intel_guc_slpc *slpc;
> - struct intel_rps *rps;
> + struct intel_guc_slpc *slpc = >->uc.guc.slpc;
> + struct intel_rps *rps = >->rps;
> struct intel_engine_cs *engine;
> enum intel_engine_id id;
> struct igt_spinner spin;
> - int err = 0;
> u32 slpc_min_freq, slpc_max_freq;
> -
> - slpc = >->uc.guc.slpc;
> - rps = >->rps;
> + int err = 0;
>
> if (!intel_uc_uses_guc_slpc(>->uc))
> return 0;
> @@ -203,69 +181,56 @@ static int live_slpc_clamp_max(void *arg)
> intel_gt_pm_get(gt);
> for_each_engine(engine, gt, id) {
> struct i915_request *rq;
> - u32 max_freq, req_freq;
> - u32 act_freq, max_act_freq;
> - u32 step;
> + u32 max_act_freq;
>
> if (!intel_engine_can_store_dword(engine))
> continue;
>
> - /* Go from max to min in 5 steps */
> - step = (slpc_max_freq - slpc_min_freq) / NUM_STEPS;
> - max_act_freq = slpc_min_freq;
> - for (max_freq = slpc_max_freq; max_freq > slpc_min_freq;
> - max_freq -= step) {
> - err = slpc_set_max_freq(slpc, max_freq);
> - if (err)
> - break;
> -
> - st_engine_heartbeat_disable(engine);
> -
> - rq = igt_spinner_create_request(&spin,
> - engine->kernel_context,
> - MI_NOOP);
> - if (IS_ERR(rq)) {
> - st_engine_heartbeat_enable(engine);
> - err = PTR_ERR(rq);
> - break;
> - }
> + st_engine_heartbeat_disable(engine);
>
> - i915_request_add(rq);
> + rq = igt_spinner_create_request(&spin,
> + engine->kernel_context,
> + MI_NOOP);
> + if (IS_ERR(rq)) {
> + err = PTR_ERR(rq);
> + st_engine_heartbeat_enable(engine);
> + break;
> + }
>
> - if (!igt_wait_for_spinner(&spin, rq)) {
> - pr_err("%s: SLPC spinner did not start\n",
> - engine->name);
> - igt_spinner_end(&spin);
> - st_engine_heartbeat_enable(engine);
> - intel_gt_set_wedged(engine->gt);
> - err = -EIO;
> - break;
> - }
> + i915_request_add(rq);
> +
> + if (!igt_wait_for_spinner(&spin, rq)) {
> + pr_err("%s: Spinner did not start\n",
> + engine->name);
> + igt_spinner_end(&spin);
> + st_engine_heartbeat_enable(engine);
> + intel_gt_set_wedged(engine->gt);
> + err = -EIO;
> + break;
> + }
>
> - delay_for_h2g();
> + switch (test_type) {
>
> - /* Verify that SWREQ indeed was set to specific value */
> - req_freq = intel_rps_read_punit_req_frequency(rps);
> + case VARY_MIN:
> + err = vary_min_freq(slpc, rps, &max_act_freq);
> + break;
> +
> + case VARY_MAX:
> + err = vary_max_freq(slpc, rps, &max_act_freq);
> + break;
>
> - /* GuC requests freq in multiples of 50/3 MHz */
> - if (req_freq > (max_freq + FREQUENCY_REQ_UNIT)) {
> - pr_err("SWReq is %d, should be at most %d\n",
> req_freq,
> - max_freq + FREQUENCY_REQ_UNIT);
> + case MAX_GRANTED:
> + /* Media engines have a different RP0 */
> + if ((engine->class == VIDEO_DECODE_CLASS) ||
> + (engine->class == VIDEO_ENHANCEMENT_CLASS)) {
> igt_spinner_end(&spin);
> st_engine_heartbeat_enable(engine);
> - err = -EINVAL;
> - break;
> + err = 0;
> + continue;
I think it's preferable to move this media engine code out of the main loop
into max_granted_freq() function if possible (maybe by faking max_act_freq
if needed)?
> }
>
> - act_freq = intel_rps_read_actual_frequency(rps);
> - if (act_freq > max_act_freq)
> - max_act_freq = act_freq;
> -
> - st_engine_heartbeat_enable(engine);
> - igt_spinner_end(&spin);
> -
> - if (err)
> - break;
> + err = max_granted_freq(slpc, rps, &max_act_freq);
> + break;
> }
>
> pr_info("Max actual frequency for %s was %d\n",
> @@ -277,31 +242,59 @@ static int live_slpc_clamp_max(void *arg)
> err = -EINVAL;
> }
>
> - if (igt_flush_test(gt->i915)) {
> - err = -EIO;
> - break;
> - }
> + igt_spinner_end(&spin);
> + st_engine_heartbeat_enable(engine);
>
> if (err)
> break;
> }
>
> - /* Restore min/max freq */
> + /* Restore min/max frequencies */
> slpc_set_max_freq(slpc, slpc_max_freq);
> slpc_set_min_freq(slpc, slpc_min_freq);
As mentioned above maybe we should restore at the beginning of the test too
(before the for_each_engine() loop) to start from a known state?
Anyway here maybe get rid of the variables and:
slpc_set_max_freq(slpc, slpc->rp0_freq);
slpc_set_min_freq(slpc, slpc->min_freq);
Thanks.
--
Ashutosh
