On Tuesday, October 17, 2017 06:01:58 PM Stefan Agner wrote: > On 2017-10-17 15:56, Bartlomiej Zolnierkiewicz wrote: > > Hi, > > > > Stefan/Shawn: > > > > Should I merge this patch? It seems to be still needed: > > > > https://www.spinics.net/lists/linux-fbdev/msg23112.html > > In my opinion yes, it fixes an issue... > > FWIW, I normally use the DRM driver when using mainline which does not > suffer from this issue, so I did not mind much that this fix never made > it... I queued your patch (with Shawn's ACK) for 4.15, thanks! Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics > -- > Stefan > > > > > 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 <stefan@xxxxxxxx> > >> > --- > >> > 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: -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
