| Message ID | 20191001080253.6135-3-icenowy@aosc.io (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/sun4i: dsi: misc timing fixes | expand |
Hi, On Tue, Oct 1, 2019 at 1:34 PM Icenowy Zheng <icenowy@aosc.io> wrote: > > According to the BSP source code, when calculating the magic DRQ value > outside burst mode, a formula of "lcd_ht - lcd_x - lcd_hbp", which is > interpreted as right margin (HFP value). However, currently the > sun6i_mipi_dsi driver code calculates it wrongly as HFP + sync length, > which lead to timing error. > > Fix the DRQ calculation by change it to use HFP. > > Signed-off-by: Icenowy Zheng <icenowy@aosc.io> > --- > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > index c86e11631ebc..2d3e822a7739 100644 > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > @@ -436,9 +436,9 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi, > SUN6I_DSI_BURST_LINE_SYNC_POINT(SUN6I_DSI_SYNC_POINT)); > > val = SUN6I_DSI_TCON_DRQ_ENABLE_MODE; > - } else if ((mode->hsync_end - mode->hdisplay) > 20) { > + } else if ((mode->hsync_start - mode->hdisplay) > 20) { > /* Maaaaaagic */ > - u16 drq = (mode->hsync_end - mode->hdisplay) - 20; > + u16 drq = (mode->hsync_start - mode->hdisplay) - 20; I have similar patch in the ML, which required commit details commented by Chen-Yu [1]. So, I'm trying to send it accordingly, let me know if you have issues. [1] https://patchwork.freedesktop.org/patch/305920/
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index c86e11631ebc..2d3e822a7739 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -436,9 +436,9 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi, SUN6I_DSI_BURST_LINE_SYNC_POINT(SUN6I_DSI_SYNC_POINT)); val = SUN6I_DSI_TCON_DRQ_ENABLE_MODE; - } else if ((mode->hsync_end - mode->hdisplay) > 20) { + } else if ((mode->hsync_start - mode->hdisplay) > 20) { /* Maaaaaagic */ - u16 drq = (mode->hsync_end - mode->hdisplay) - 20; + u16 drq = (mode->hsync_start - mode->hdisplay) - 20; drq *= mipi_dsi_pixel_format_to_bpp(device->format); drq /= 32;
According to the BSP source code, when calculating the magic DRQ value outside burst mode, a formula of "lcd_ht - lcd_x - lcd_hbp", which is interpreted as right margin (HFP value). However, currently the sun6i_mipi_dsi driver code calculates it wrongly as HFP + sync length, which lead to timing error. Fix the DRQ calculation by change it to use HFP. Signed-off-by: Icenowy Zheng <icenowy@aosc.io> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)