On Wed, Feb 13, 2019 at 7:44 PM Andrzej Hajda <a.hajda@xxxxxxxxxxx> 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@xxxxxxxxx
> <mailto:simhavcs@xxxxxxxxx>> 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.
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@xxxxxxxx
> <mailto:daniel@xxxxxxxx>> 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
> > >
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> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
>
>
>
> --
> regards,
> vinaysimha
>
>
>
> --
> regards,
> vinaysimha
regards,
vinaysimha
vinaysimha
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