Hi Sakari, Thanks for reviewing the patch. On Wed, 2019-08-07 at 15:06 +0300, Sakari Ailus wrote: > On Tue, Jul 30, 2019 at 05:14:24AM -0300, Ezequiel Garcia wrote: > > Hey Hans, > > > > On Mon, 2019-07-01 at 08:48 +0200, Philipp Zabel wrote: > > > On Thu, 2019-06-27 at 19:29 -0300, Fabio Estevam wrote: > > > > From: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> > > > > > > > > Not all sensors will be able to guarantee a proper initial state. > > > > This may be either because the driver is not properly written, > > > > or (probably unlikely) because the hardware won't support it. > > > > > > > > While the right solution in the former case is to fix the sensor > > > > driver, the real world not always allows right solutions, due to lack > > > > of available documentation and support on these sensors. > > > > > > > > Let's relax this requirement, and allow the driver to support stream start, > > > > even if the sensor initial sequence wasn't the expected. > > > > > > > > Also improve the warning message to better explain the problem and provide > > > > a hint that the sensor driver needs to be fixed. > > > > > > > > Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> > > > > Signed-off-by: Fabio Estevam <festevam@xxxxxxxxx> > > > > > > Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > > > > > > This seems ready to pick and it has Philipp's and Steve's RB. > > Hi Ezequiel, > > In general the LP-11 condition should be detected by hardware (or firmware) > in such a way that it's detected even if a transmitter that holds the state > just a short period of time. In other words, software is not supposed to be > even testing for it. > > Have you checked how it works if you simply leave out this test? > The current change relaxes a condition, which we observed was too strict. Some drivers might be unable to enter LP-11 state, but I don't think that's a reason to fail capture. We had to fix at least OV5645 and OV5640 recently because of this, and I can imagine more drivers will have the same issue. The way I see it, the driver is imposing a condition that is too strict, and that's why relaxing it makes sense. No, regarding removing the test completely, I'm not sure I want to propose such a change, which would be undoubtfully more invasive. Thanks, Ezequiel
