Re: [PATCH 12/17] OMAPDSS: clean up dss_mgr_set_timings

On Wednesday 05 September 2012 05:11 PM, Tomi Valkeinen wrote:

On Wed, 2012-09-05 at 17:04 +0530, Archit Taneja wrote:

quoted

On Wednesday 05 September 2012 04:11 PM, Tomi Valkeinen wrote:

quoted

On Wed, 2012-09-05 at 14:45 +0530, Archit Taneja wrote:

quoted

On Wednesday 05 September 2012 01:55 PM, Tomi Valkeinen wrote:

quoted

dss_mgr_set_timings() can only be called when the output is not active.
This means that most of the code in the function is extra, as there's no
need to write the values to registers, etc, because that will be handled
when the output will be enabled.

We need to fix dpi_set_timings() before we can make this change. DPI
still tries to change timings on the fly, i.e, with manager enabled. We
need to disable and enable the DPI output like we do for other outputs.

Yep, and for HDMI also (I didn't check the others yet).

I don't think HDMI is impacted, we do the full power off and power on
for HDMI, so the manager would be disabled when we set the timings.

Ah right.

quoted

quoted

I think the simplest way to handle this is to only write the dpi.timings
in omapdss_dpi_set_timings, and remove the call to dss_mgr_set_timings.
This is not perfect, as a call to omapdss_dpi_set_timings when the
display is enabled would result in changing the dpi.timings, but the
changes wouldn't be actually in use.

The simplest way would be to do what other outputs do, disable the
output and re-enable the output with the new timings value, if the panel
is enabled.

Not quite, as there's the mutex in dpi so we can't call enable/disable
from set_timings. I could create separate non-locked internal functions
for enable and disable, but that feels more complex than just removing
the enable & disable from set_timings.

Okay, right.

In the end we'll anyway only allow changing timings when the output is
disabled.

The only change I had to do, in addition to removing code from
set_timings functions, was to add display disable & enable calls to the
"timings" sysfs write. omapfb already only calls set_timings when the
output is disabled, and omapdrm does the same.

Okay, that sounds good then.

Archit