[Intel-gfx] [PATCH i-g-t] tests/chamelium: Require HPD storm control for basic hotplug test

[Paul Kocialkowski]

Hi,

On Tue, 2017-06-13 at 14:20 -0400, Lyude Paul wrote:
> NAK, igt_hpd_storm_set_threshold is expected to be called in both
> situations with and without hpd storm control support. The function
> should be able to notice when the host doesn't have the debugfs nodes
> for hpd storm control, and just return without doing anything in that
> case:
> 
> void igt_hpd_storm_set_threshold(int drm_fd, unsigned int threshold)
> {
> 	int fd = igt_debugfs_open(drm_fd, "i915_hpd_storm_ctl", O_WRONLY);
> 	char buf[16];
> 
> 	/* Right here is where we should be exiting if we don't have the debugfs
> file present */
> 	if (fd < 0)
> 		return;
> 
> 	igt_debug("Setting HPD storm threshold to %d\n", threshold);
> 	snprintf(buf, sizeof(buf), "%d", threshold);
> 	igt_assert_eq(write(fd, buf, strlen(buf)), strlen(buf));
> 
> 	close(fd);
> 	igt_install_exit_handler(igt_hpd_storm_exit_handler);
> }
> 
> The igt asserts that come after that are there because if we do have
> the i915_hpd_storm_ctl file but it doesn't do what we expect it to,
> then that's probably an error. This being said, adding a call to
> igt_require_hpd_storm_ctl(data->drm_fd); will result in the hotplugging
> tests being skipped on every non-intel platform.

That is the expected behavior, the test should definitely be skipped when the
debugfs node is not available. Without requiring hpd storm ctl,
test_basic_hotplug will fail at reprobe_connector according to the following
log:

IGT-Version: 1.19-g5d494bda (x86_64) (Linux: 4.11.3-1-ARCH x86_64)
(chamelium:523) CRITICAL: Test assertion failure function test_basic_hotplug,
file chamelium.c:166:
(chamelium:523) CRITICAL: Failed assertion: reprobe_connector(data, port) ==
DRM_MODE_CONNECTED
(chamelium:523) CRITICAL: error: 2 != 1
Stack trace:
  #0 [__igt_fail_assert+0xef]
  #1 [test_basic_hotplug.constprop.20+0x157]
  #2 [__real_main588+0xe88]
  #3 [main+0x33]
  #4 [__libc_start_main+0xea]
  #5 [_start+0x2a]
Subtest dp-hpd failed.
**** DEBUG ****
(chamelium:523) igt-chamelium-DEBUG: Resetting the chamelium
(chamelium:523) DEBUG: Waiting for DP-1 to disconnect...
(chamelium:523) DEBUG: Reprobing DP-1...
(chamelium:523) igt-debugfs-DEBUG: Opening debugfs directory
'/sys/kernel/debug/dri/0'
(chamelium:523) igt-chamelium-DEBUG: Plugging DP-1
(chamelium:523) DEBUG: Reprobing DP-1...
(chamelium:523) CRITICAL: Test assertion failure function test_basic_hotplug,
file chamelium.c:166:
(chamelium:523) CRITICAL: Failed assertion: reprobe_connector(data, port) ==
DRM_MODE_CONNECTED
(chamelium:523) CRITICAL: error: 2 != 1
****  END  ****
Subtest dp-hpd: FAIL (1.383s)
Test requirement not met in function require_connector_present, file
chamelium.c:99:
Test requirement: found
No port of type HDMI-A was found
Test requirement not met in function require_connector_present, file
chamelium.c:99:
Test requirement: found
No port of type VGA was found

> Are these tests no longer working on systems without hpd storm control?
> The last time I tested it I didn't see any issues, but that was a while
> ago.
>
> On Tue, 2017-06-13 at 15:46 +0300, Paul Kocialkowski wrote:
> > On Tue, 2017-06-13 at 15:44 +0300, Paul Kocialkowski wrote:
> > > The basic hotplug test (test_basic_hotplug) makes calls to
> > > igt_hpd_storm_set_threshold, which requires HPD storm control.
> > > 
> > > This adds a check for that control, since it was missing.
> > 
> > This is a resend of yesterday's patch with the right subject prefix
> > so that
> > patchwork can pick it up.
> > 
> > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski at linux.intel.com
> > > > 
> > > 
> > > ---
> > >  tests/chamelium.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/tests/chamelium.c b/tests/chamelium.c
> > > index 2e14ccb9..bd7772f8 100644
> > > --- a/tests/chamelium.c
> > > +++ b/tests/chamelium.c
> > > @@ -153,6 +153,8 @@ test_basic_hotplug(data_t *data, struct
> > > chamelium_port
> > > *port)
> > >  	struct udev_monitor *mon = igt_watch_hotplug();
> > >  	int i;
> > >  
> > > +	igt_require_hpd_storm_ctl(data->drm_fd);
> > > +
> > >  	reset_state(data, port);
> > >  	igt_hpd_storm_set_threshold(data->drm_fd, 0);
> > >  
-- 
Paul Kocialkowski <paul.kocialkowski at linux.intel.com>
Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo