Hi Philippe, On Monday, 14 May 2018 21:58:48 EEST Philippe CORNU wrote: > On 05/14/2018 12:33 PM, Andrzej Hajda wrote: > > On 14.05.2018 11:38, Philippe CORNU wrote: > >> On 04/25/2018 09:53 AM, Philippe Cornu wrote: > >>> Add the optional power supplies using the description found in > >>> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)". > >>> > >>> The sii902x input IOs are not "io safe" so it is important to > >>> enable/disable voltage regulators during probe/remove phases to > >>> avoid damages. > > > > What exactly does it mean? Ie I understand that the chip has some > > limitations, but why enabling/disabling regulators in probe/remove > > should solve it? > > thank you for your comment. > > And sorry for the "bad" explanation in the 2nd paragraph about the fact > that inputs are not "io safe". I added this 2nd paragraph in v2 > following a good comment from Laurent on adding the management of the > regulators outside the probe/remove for a better power consumption > management (enable/disable regulators only when the ic is used for > displaying something for instance...). But after a deeper analysis, I > realized that the only way to improve the power consumption is to > implement & test the sii902x various sleep modes, that is out-of-scope > of this small patch and also out-of-scope of my test board I use on > which the sii902x bridge ic power consumption is very low compare to the > rest of the system... > > I will remove this "explanation" in v3 as it creates confusion. I'd rather keep it and expand it explain why enabling/disabling regulators at probe/remove solves the problem. Your patch otherwise looks OK (although if you submit a v3 anyway you could also rename err_disable_regulator to err_disable_regulators). > >>> Signed-off-by: Philippe Cornu <philippe.cornu@xxxxxx> > >>> --- > >>> > >>> drivers/gpu/drm/bridge/sii902x.c | 38 ++++++++++++++++++++++++++++++---- > >>> 1 file changed, 34 insertions(+), 4 deletions(-) -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
