Hi, Stefan/Shawn:
Should I merge this patch? It seems to be still needed: https://www.spinics.net/lists/linux-fbdev/msg23112.html Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics On Friday, May 06, 2016 01:29:59 PM Stefan Agner wrote: > Hi Shawn, > > On 2016-01-25 17:29, Stefan Agner wrote: > > The PIXDATA flags of the display_flags enum are controller centric, > > e.g. NEGEDGE means the controller shall drive the data signals on > > pixelclocks negative edge. However, the drivers flag is display > > centric: Sample the data on negative (falling) edge. > > > > Therefore, change the if statement to check for the POSEDGE flag > > (which is typically not set): > > Drive on positive edge => sample on negative edge > > Any comment on that patch? > > -- > Stefan > > > > > > Signed-off-by: Stefan Agner <ste...@agner.ch> > > --- > > Hi all > > > > Shawn, I would like to have at least your Ack on this before merge. > > > > It seems that this has been wrong since the driver is able to use > > the timings from the device tree, introduced with 669406534b4a > > ("video: mxsfb: get display timings from device tree"). > > > > Not sure how many device trees actually specify the wrong pixel clock > > polarity due to that. At least the initial flag convertion from the > > old platform data structures done with 0d9f8217db15 ("ARM: mxs: move > > display timing configurations into device tree") seems to be affected > > and would need to be changed accordingly... > > > > Not sure how we should handle this, maybe just invert all > > pixelclk-active properties where the mxsfb driver is in use...? > > > > -- > > Stefan > > > > drivers/video/fbdev/mxsfb.c | 13 +++++++++++-- > > 1 file changed, 11 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c > > index 4e6608c..38898a9 100644 > > --- a/drivers/video/fbdev/mxsfb.c > > +++ b/drivers/video/fbdev/mxsfb.c > > @@ -150,7 +150,7 @@ > > #define STMLCDIF_24BIT 3 /** pixel data bus to the display is of 24 > > bit width */ > > > > #define MXSFB_SYNC_DATA_ENABLE_HIGH_ACT (1 << 6) > > -#define MXSFB_SYNC_DOTCLK_FALLING_ACT (1 << 7) /* negtive edge > > sampling */ > > +#define MXSFB_SYNC_DOTCLK_FALLING_ACT (1 << 7) /* negative edge > > sampling */ > > > > enum mxsfb_devtype { > > MXSFB_V3, > > @@ -788,7 +788,16 @@ static int mxsfb_init_fbinfo_dt(struct mxsfb_info > > *host, > > > > if (vm.flags & DISPLAY_FLAGS_DE_HIGH) > > host->sync |= MXSFB_SYNC_DATA_ENABLE_HIGH_ACT; > > - if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE) > > + > > + /* > > + * The PIXDATA flags of the display_flags enum are controller > > + * centric, e.g. NEGEDGE means drive data on negative edge. > > + * However, the drivers flag is display centric: Sample the > > + * data on negative (falling) edge. Therefore, check for the > > + * POSEDGE flag: > > + * drive on positive edge => sample on negative edge > > + */ > > + if (vm.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE) > > host->sync |= MXSFB_SYNC_DOTCLK_FALLING_ACT; > > > > put_display_node:
