Hi, On Fri, Oct 13, 2023 at 2:43 PM Doug Anderson <dianders@xxxxxxxxxx> wrote: > > Hi, > > On Fri, Oct 13, 2023 at 2:19 AM Cong Yang > <yangcong5@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > At present, we have found that there may be a problem of blurred > > screen during fast sleep/resume. The direct cause of the blurred > > screen is that the IC does not receive 0x28/0x10. Because of the > > particularity of the IC, before the panel enters sleep hid must > > stop scanning, as i2c_hid_core_suspend before ili9882t_disable. > > If move the ili9882t_enter_sleep_mode function to ili9882t_unprepare, > > touch reset will pull low before panel entersleep, which does not meet > > the timing requirements.. So in order to solve this problem, the IC > > can handle it through the exception mechanism when it cannot receive > > 0x28/0x10 command. Handling exceptions requires a reset 50ms delay. > > Refer to vendor detailed analysis [1]. > > > > Ilitek vendor also suggested switching the page before entering sleep to > > avoid panel IC not receiving 0x28/0x10 command. > > > > Note: 0x28 is display off, 0x10 is sleep in. > > > > [1]: https://github.com/ILITEK-LoganLin/Document/tree/main/ILITEK_Power_Sequence > > > > Signed-off-by: Cong Yang <yangcong5@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/panel/panel-ilitek-ili9882t.c | 22 ++++++++++++++++++- > > 1 file changed, 21 insertions(+), 1 deletion(-) > > As talked about in response to the previous version [1], we can work > to see if we can improve the sequencing. However, for now this seems > fine. > > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > > [1] https://lore.kernel.org/r/CAD=FV=W_LT9mPYKjaKP3OvUDeNpsZxkhVN9NP_hQ+Es6Fe3dVw@xxxxxxxxxxxxxx Pushed to drm-misc-next: 5820a1932ce8 drm/panel: ili9882t: Avoid blurred screen from fast sleep
