Date: Fri, 10 Jul 2015 11:10:30 -0700 From: Adrian Chadd <adrian.chadd@gmail.com> To: Eric McCorkle <eric@metricspace.net> Cc: "freebsd-mobile@freebsd.org" <freebsd-mobile@freebsd.org>, "freebsd-acpi@freebsd.org" <freebsd-acpi@freebsd.org> Subject: Re: Attempting to diagnose suspend/resume issue Message-ID: <CAJ-Vmo=TTbBDfkJXeU%2Bbmtx99YxWpNkGcSgc37EpdYoz4us2jw@mail.gmail.com> In-Reply-To: <559F4B70.8060402@metricspace.net> References: <559F4B70.8060402@metricspace.net>
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Hi, can you post some more debugging showing that the VGA driver is restoring the VGA state before the power is applied? Thanks! -a On 9 July 2015 at 21:34, Eric McCorkle <eric@metricspace.net> wrote: > A long while ago, I reported my screen not coming back on after resume, > shortly after r274386 went in. Unfortunately, the follow-on patch > didn't seem to work for me. > > (r274386 changed the way devices get powered down/up, and r274397 fixed > a typo in r274386 that tried to power down/up the wrong devices.) > > I finally found the time to try and track this thing down, and I got > some information that might prove useful in tracking it down. > > > * The screen comes back up only for syscons in pixel mode up to r274835. > As far as I can tell, it doesn't work for vt in any revision (not as > sure about text-mode syscons, but there is at least one revision where > it works for pixel mode, but not text mode) > > * Comparing logs from r274385 and r274397, it seems the likely cause is > that the changes in r274386 reordered things so that the VGA driver > attempts to restore the state of the card before its power has been > turned back on (you can clearly see this happening, and you can see the > attempt to restore the state failing). > > * Suspend/resume works fine in Linux (I'm not sure how to get linux to > printout a debug trace similar to debug.bootverbose), so the hardware > can't be /that/ broken. > > * The order in which things happen during resume seems to be different > between vt and syscons resumes, though I can't tell where vt restores > the state of the card (or the efifb device) > > My guess as to the likely cause is that vt also tries to restore the > state of the card before its power has been turned back on similar to > what syscons does after r274386, or else the dual happens during suspend > (it tries to save the state after the device is powered down). It does > seem a little wierd that syscons would behave differently in that > respect for pixel mode vs text mode, though. > > I'm open to suggestions as to what to look at next, or theories as to > what might be the culprit. I also have dmesg logs for the various > revisions and drivers. > > Best, > Eric >
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