On 12/4/2015 8:52 PM, Imre Deak wrote:
On to, 2015-12-03 at 16:43 -0800, Bob Paauwe wrote:On Tue, 1 Dec 2015 19:43:05 +0200 Imre Deak <imre.deak@xxxxxxxxx> wrote:On ti, 2015-12-01 at 09:22 -0800, Bob Paauwe wrote:On Tue, 1 Dec 2015 15:56:55 +0200 Imre Deak <imre.deak@xxxxxxxxx> wrote:On ma, 2015-11-30 at 16:23 -0800, Bob Paauwe wrote:Now that the frequency can drop below the user specified minimum when the gpu is idle, add some checking to verify that it really does drop down to the RPn frequency in specific cases. To do this, modify the main test flow to take two 'check' routines instead of one. When running the config-min-max-idle subtest make use of the second check routine to verify that the frequency drops to RPn instead of simply <= user min frequency. For all other subtests, use the original check routines for both checks. Signed-off-by: Bob Paauwe <bob.j.paauwe@xxxxxxxxx>I don't see the point. The frequency should always drop to the idle frequency if the GPU is idle, it's not enough that it's below MIN- freq. So why do we need separate CUR-freq<=MIN-freq and CUR- freq==idle- freq checks?I started from the premise that it should always drop to idle but that's just not the case.It is the correct premise and if it doesn't hold then there is a real bug either in the testcase or the kernel which needs to be addressed differently. I haven't found anything concrete but one suspect is the logic that waits for the GPU idle condition, maybe the timeout value idle_check() or the hard-coded duration in do_load_gpu() is incorrect. In any case let's not paper over this issue, the very reason we have test cases is to uncover such bugs.The min_max_config() function is used for both the idle and loaded subtests. If you try to check for freq=idle when doing the loaded subtest it will fail since it never goes idle. Even in the idle subtest there are cases where it doesn't drop down to idle.The only place we should check for freq==idle is in idle_check() and that one is not called during the loaded subtest, it wouldn't even make sense to do so. So I'm not sure how this subtest fails for you.I suppose I could duplicate min_max_config and have a min_max_config_idle() and min_max_conifg_not_idle() for use by the different subtests.The point of the "check" argument of min_max_config() is to distinguish between the idle and loaded cases. The check functions passed in know already if they can expect the frequency to reach the idle frequency or not.The real problem is that the test was not designed to handle the case where the freq could drop below min and probably needs to be re-designed. I've been trying to find a quick fix vs. a complete overhaul as this isn't really a priority for me.I think we only need your first patch and if there is any failure after that we have to root cause that and fix it properly. --ImreYou're right. I'm working with BXT and it seems like it's got some unique issues with RPS. I just sent a new patch based on the first one but with the changes you suggested to check for ==idle instead of <=min. Maybe you have some insights into what I'm seeing with BXT? The first problem I had was that I would see threshold up interrupts but not any threshold down interrupts. The missing down interrupts was related to the BIOS setting. I had runtime PM disabled so it seems strange that I was getting the up interrupts.
How was runtime pM disabled? Think RPM and RPS are not related.
FYI Turbo is disabled until A1 due to issues with RC6 enabled. Which registers exactly do we need to check from BIOS RPS programming perspective? I see that RP control is set by BIOS ... Is that check enough?Yes, I saw this too. I wonder if we could check this somehow and not enable RPS if BIOS hasn't set things up properly. Sagar has a patch that checks the RC6 setup [1]; that's not exactly RPS, but since they are setup at the same place I think we could use that for now for RPS too.
With the BIOS setting corrected, the driver started disabling the down interrupts once the freq dropped to min or just below because of the min vs. idle difference. I have a patch for this that I'll send shortly.Hm, that's not necessarily a problem. To reach the idle frequency we don't depend on the up/down interrupts. The idle frequency gets set explicitly from intel_mark_idle(), so if you don't reach the idle freq then this function doesn't get called for some reason. Or as I said earlier we just don't wait enough in do_load_gpu() or idle_check() in the test, so we read out cur-freq before intel_mark_idle() would get called.The remaining issue seems to be some type of timing issue. I've had to add a 35000us sleep between updating the interrupt enable register (0xA168) and the posting read of freq. register (0xA008), otherwise it acts like the change to the interrupt enable register never happened. None of the documentation I have indicates that this is needed.What happens exactly? The frequency gets stuck above min-freq and you never get a down interrupt? Not sure how this could happen, but there is an interesting comment in intel_rps_limits() about this scenario. --Imre [1] http://lists.freedesktop.org/archives/intel-gfx/2015-November/07938 6.htmlBob--- tests/pm_rps.c | 47 ++++++++++++++++++++++++++++++++++---- ---- ----- 1 file changed, 34 insertions(+), 13 deletions(-) diff --git a/tests/pm_rps.c b/tests/pm_rps.c index f919625..96225ce 100644 --- a/tests/pm_rps.c +++ b/tests/pm_rps.c @@ -364,7 +364,7 @@ static int get_hw_rounded_freq(int target) return ret; }-static void min_max_config(void (*check)(void), boolload_gpu) +static void min_max_config(void (*check)(void), void (*check2)(void), bool load_gpu) { int fmid = (origfreqs[RPn] + origfreqs[RP0]) / 2;@@ -384,7 +384,7 @@ static void min_max_config(void(*check)(void), bool load_gpu) writeval(stuff[MAX].filp, origfreqs[RP0]); if (load_gpu) do_load_gpu(); - check(); + check2();igt_debug("\nIncrease min to midpoint...\n");writeval(stuff[MIN].filp, fmid); @@ -412,7 +412,7 @@ static void min_max_config(void (*check)(void), bool load_gpu) writeval(stuff[MIN].filp, origfreqs[RPn]); if (load_gpu) do_load_gpu(); - check(); + check2();igt_debug("\nDecrease min below RPn(invalid)...\n"); writeval_inval(stuff[MIN].filp, 0); @@ -420,11 +420,11 @@ static void min_max_config(void (*check)(void), bool load_gpu)igt_debug("\nDecrease max to midpoint...\n");writeval(stuff[MAX].filp, fmid); - check(); + check2();igt_debug("\nDecrease max to RPn...\n");writeval(stuff[MAX].filp, origfreqs[RPn]); - check(); + check2();igt_debug("\nDecrease max below RPn(invalid)...\n"); writeval_inval(stuff[MAX].filp, 0); @@ -436,11 +436,11 @@ static void min_max_config(void (*check)(void), bool load_gpu)igt_debug("\nIncrease max to midpoint...\n");writeval(stuff[MAX].filp, fmid); - check(); + check2();igt_debug("\nIncrease max to RP0...\n");writeval(stuff[MAX].filp, origfreqs[RP0]); - check(); + check2();igt_debug("\nIncrease max above RP0(invalid)...\n"); writeval_inval(stuff[MAX].filp, origfreqs[RP0] + 1000); @@ -461,7 +461,7 @@ static void basic_check(void)#define IDLE_WAIT_TIMESTEP_MSEC 100#define IDLE_WAIT_TIMEOUT_MSEC 10000 -static void idle_check(void) +static void idle_check_min(void) { int freqs[NUMFREQ]; int wait = 0; @@ -482,6 +482,27 @@ static void idle_check(void) igt_debug("Required %d msec to reach cur<=min\n", wait); }+static void idle_check_idle(void)+{ + int freqs[NUMFREQ]; + int wait = 0; + + /* Monitor frequencies until cur settles down to min, which should + * happen within the allotted time */ + do { + read_freqs(freqs); + dump(freqs); + checkit(freqs); + if (freqs[CUR] == freqs[RPn]) + break; + usleep(1000 * IDLE_WAIT_TIMESTEP_MSEC); + wait += IDLE_WAIT_TIMESTEP_MSEC; + } while (wait < IDLE_WAIT_TIMEOUT_MSEC); + + igt_assert_eq(freqs[CUR], freqs[RPn]); + igt_debug("Required %d msec to reach cur=idle\n", wait); +} + #define LOADED_WAIT_TIMESTEP_MSEC 100 #define LOADED_WAIT_TIMEOUT_MSEC 3000 static void loaded_check(void) @@ -577,7 +598,7 @@ static void reset(void)igt_debug("Removing load...\n");load_helper_stop(); - idle_check(); + idle_check_min(); }/*@@ -635,7 +656,7 @@ static void blocking(void) matchit(pre_freqs, post_freqs);igt_debug("Removing load...\n");- idle_check(); + idle_check_min(); }static void pm_rps_exit_handler(int sig)@@ -686,14 +707,14 @@ igt_main }igt_subtest("basic-api")- min_max_config(basic_check, false); + min_max_config(basic_check, basic_check, false);igt_subtest("min-max-config-idle")- min_max_config(idle_check, true); + min_max_config(idle_check_min, idle_check_idle, true);igt_subtest("min-max-config-loaded") {load_helper_run(HIGH); - min_max_config(loaded_check, false); + min_max_config(loaded_check, loaded_check, false); load_helper_stop(); }_______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
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