drm bridge control from another driver
Vinay Simha B N
simhavcs at gmail.com
Mon Feb 18 15:19:19 UTC 2019
added the temperature alert irq handler in adv driver , in the irq
calling schedule_work(&adv7511->hpd_work); , initially in the
adv7511_detect , if we set status = connector_status_disconnected; later
when irq handler calls the schedule work, hpd does not works.
[ 55.052677] [drm] Cannot find any crtc or sizes
[ 55.058786] [drm] Cannot find any crtc or sizes
by default driver of adv, hpd does not works as expected, board boots
without hdmi connected, after postboot if we connect hdmi , in irq hpd_work
,but to get the display we need to press ctrl+alt+backspace.
On Thu, Feb 14, 2019 at 8:03 PM Andrzej Hajda <a.hajda at samsung.com> wrote:
> On 13.02.2019 15:31, Vinay Simha B N wrote:
> >
> >
> > On Wed, Feb 13, 2019 at 7:44 PM Andrzej Hajda <a.hajda at samsung.com
> > <mailto:a.hajda at samsung.com>> wrote:
> >
> > On 13.02.2019 14:40, Vinay Simha B N wrote:
> > > Andrzej/Daniel,
> > >
> > > please suggest any input on the scenario for temperature control
> and
> > > dsi bridge enable/disable.
> > >
> > > On Mon, Feb 11, 2019 at 2:41 PM Vinay Simha B N
> > <simhavcs at gmail.com <mailto:simhavcs at gmail.com>
> > > <mailto:simhavcs at gmail.com <mailto:simhavcs at gmail.com>>> wrote:
> > >
> > > dsi2hdmi(adv7511) chip operating temperature range is -10 degC
> > > to +85 degC. We want to enable/disable the bridge only when
> > > temperature range is inbetween these range.
> > >
> > > We have temperature control chip to read the temp, tLow an
> tHigh
> > > can be set. whenever interrupt(alert) triggers we want to
> > > enablel/disable the bridge.
> > >
> > > Any suggestion what is the better way to handle this scenario?
> > >
> >
> > Why do you need to bother about this quite big range at all?
> >
> > we are looking for -10 deg C, this system will be used in a place
> > where temp goes beyond -20 deg C... processor(apq8016/410c) can handle
> > upto -30, but dsi2hdmi(adv7533) chip if enabled beyond -10 deg C, life
> > of the chip goes down or it cannot operate at all.
> >
> >
> > I guess the best would be to set whole platform operating temperature
> > range, and poweroff/sleep/slow down/??? whole system, not just one
> > random chip, which probably is not the most fragile piece, am I
> right?
> >
> > right now we are focused only to disable the hdmi chip if temp goes
> > beyond -10, since this is only chip in board faces temp issue, other
> > components are fine to go upto -30 deg C.
> >
> >
> > If you really insist on handling it per chip, you can try to
> > investigate
> > following paths:
> >
> > 1. Just disable the chip, without noticing drm, other drivers, or
> > userspace, and re-enable it if temperature become acceptable, but I
> am
> > not sure if this will not change behavior of other chips.
> >
> > dsi2hdmi tied with drm framework, i need to enable/disable the bridge.
> > i can disable the regulators enabled for it , but this does not work
> > as we want.
> >
> >
> > 2. Disable the chip and report to the drm subsystem
> > connector_status_disconnected - this will cause drm to stop display
> > pipeline and userspace notification.
> >
> > any references/driver on how to disable and report to drm susbsystem
> > will help to implement.
> > connector_status_disconnected i need to call in the interrupt handler
> > of tmp102 driver.
>
>
> Look at the code of adv7511_hpd_work, it evaluates connector status
> based on ADV7511_REG_STATUS, so you can put there temperature check
> also, and call 'schedule_work(&adv7511->hpd_work)'
>
> if temperature passes valid temp range.
>
> If you want to do it in mainline, please consult it with adv7511
> authors/commiters.
>
>
> Regards
>
> Andrzej
>
>
> >
> > in userspace when i tried manually below commands, there is no impact
> > in the display.
> > /sys/class/drm/card0-HDMI-A-1/status
> > echo off > status
> > echo on > status
> >
> >
> > Regards
> >
> > Andrzej
> >
> >
> > >
> > > regards,
> > > vinaysimha
> > >
> > > On Mon, Feb 11, 2019 at 2:10 PM Daniel Vetter
> > <daniel at ffwll.ch <mailto:daniel at ffwll.ch>
> > > <mailto:daniel at ffwll.ch <mailto:daniel at ffwll.ch>>> wrote:
> > >
> > > On Mon, Feb 11, 2019 at 09:32:54AM +0100, Andrzej Hajda
> > wrote:
> > > > On 11.02.2019 07:52, Vinay Simha B N wrote:
> > > > > hi,
> > > > >
> > > > > is it possible to control the drm bridge from another
> > > driver in irq
> > > > > handler(enable/disable the bridge)?
> > > >
> > > >
> > > > If you mean 'in irq context' the answer is no, usually
> > > enable/disable
> > > > callbacks can sleep, so cannot be called from atomic
> > context.
> > > >
> > > >
> > > > >
> > > > > is there a way to control the "dpms force off" and
> "dpms
> > > force on" in
> > > > > the interrupt handler?
> > > >
> > > >
> > > > Could you elaborate more on both subjects.
> > >
> > > Yeah, please explain what you want to use this for. dpms
> > on/off is
> > > controlled by userspace, the kernel should not change that
> > > state behind
> > > usersapce's back. If this is for some manuel refresh
> > display,
> > > then that's
> > > a bit a different story ofc, but for that you don't want
> > to do
> > > a real dpms
> > > force off/on.
> > > -Daniel
> > > >
> > > >
> > > > Regards
> > > >
> > > > Andrzej
> > > >
> > > >
> > > > >
> > > > > --
> > > > > regards,
> > > > > vinaysimha
> > > > >
> > > > > _______________________________________________
> > > > > dri-devel mailing list
> > > > > dri-devel at lists.freedesktop.org
> > <mailto:dri-devel at lists.freedesktop.org>
> > > <mailto:dri-devel at lists.freedesktop.org
> > <mailto:dri-devel at lists.freedesktop.org>>
> > > > >
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > > >
> > > >
> > > > _______________________________________________
> > > > dri-devel mailing list
> > > > dri-devel at lists.freedesktop.org
> > <mailto:dri-devel at lists.freedesktop.org>
> > > <mailto:dri-devel at lists.freedesktop.org
> > <mailto:dri-devel at lists.freedesktop.org>>
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> > >
> > > --
> > > Daniel Vetter
> > > Software Engineer, Intel Corporation
> > > http://blog.ffwll.ch
> > >
> > >
> > >
> > > --
> > > regards,
> > > vinaysimha
> > >
> > >
> > >
> > > --
> > > regards,
> > > vinaysimha
> >
> >
> >
> >
> > --
> > regards,
> > vinaysimha
>
>
>
--
regards,
vinaysimha
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