From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/i915: Synchronize hpd work in i915_hpd_storm_ctl_show() Date: Wed, 21 Nov 2018 11:06:16 +0100 Message-ID: <20181121100616.GR4266@phenom.ffwll.local> References: <20181121003718.17704-1-lyude@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20181121003718.17704-1-lyude@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Lyude Paul Cc: intel-gfx@lists.freedesktop.org, David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Rodrigo Vivi List-Id: intel-gfx@lists.freedesktop.org On Tue, Nov 20, 2018 at 07:37:17PM -0500, Lyude Paul wrote: > While trying to add a chamelium test for short HPD IRQs, I ran into > issues where a hotplug storm would be triggered, but the point at which > it would be reported by the kernel would be after igt actually finished > checking i915_hpd_storm_ctl's status. So, fix this by simply > synchronizing our IRQ work, dig_port_work, and hotplug_work before > printing out the HPD storm status in i915_hpd_storm_ctl_show(). > > Signed-off-by: Lyude Paul > Cc: Ville Syrjälä Makes sense. Reviewed-by: Daniel Vetter > --- > drivers/gpu/drm/i915/i915_debugfs.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index 69447c68b9af..af4268a6d2d9 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -4592,6 +4592,13 @@ static int i915_hpd_storm_ctl_show(struct seq_file *m, void *data) > struct drm_i915_private *dev_priv = m->private; > struct i915_hotplug *hotplug = &dev_priv->hotplug; > > + /* Synchronize with everything first in case there's been an HPD > + * storm, but we haven't finished handling it in the kernel yet > + */ > + synchronize_irq(dev_priv->drm.irq); > + flush_work(&dev_priv->hotplug.dig_port_work); > + flush_work(&dev_priv->hotplug.hotplug_work); > + > seq_printf(m, "Threshold: %d\n", hotplug->hpd_storm_threshold); > seq_printf(m, "Detected: %s\n", > yesno(delayed_work_pending(&hotplug->reenable_work))); > -- > 2.19.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch