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| author | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2015-04-10 12:48:38 +0300 |
|---|---|---|
| committer | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2015-06-17 15:44:29 +0300 |
| commit | 7059e3d8d8f0d716f8a6664f365bcbef9d147905 (patch) | |
| tree | 3743162de783f4659f7298353bce3a6f45676e2f /drivers/video | |
| parent | 3ce17b48da85d89769609c4302a016a1af63cfda (diff) | |
| download | linux-7059e3d8d8f0d716f8a6664f365bcbef9d147905.tar.xz | |
OMAPDSS: DISPC: do only y decimation on OMAP3
The current driver does both x and y decimation on OMAP3 DSS. Testing
shows that x decimation rarely works, leading to underflows.
The exact reason for this is unclear, as the underflows seem to happen
even with low pixel clock rates, and I would presume that if the DSS can
manage a display with 140MHz pixel clock, it could manage x decimation
with factor 2 with a low pixel clock (~30MHz).
So it is possible that there is a problem somewhere else, in memory
management, or DSS DMA, or similar. I have not found anything that would
help this.
So, to fix the downscaling scaling, this patch removes x decimation for
OMAP3. This will limit some of the more demanding downscaling scenarios,
but one could argue that using DSS to downscale such a large amount is
insane in the first place, as the produced image is rather bad quality.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/omap2/dss/dispc.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/drivers/video/fbdev/omap2/dss/dispc.c b/drivers/video/fbdev/omap2/dss/dispc.c index 0bdb587cb48c..646d94a71a79 100644 --- a/drivers/video/fbdev/omap2/dss/dispc.c +++ b/drivers/video/fbdev/omap2/dss/dispc.c @@ -2300,7 +2300,6 @@ static int dispc_ovl_calc_scaling_34xx(unsigned long pclk, unsigned long lclk, { int error; u16 in_width, in_height; - int min_factor = min(*decim_x, *decim_y); const int maxsinglelinewidth = dss_feat_get_param_max(FEAT_PARAM_LINEWIDTH); @@ -2349,16 +2348,8 @@ again: } } - if (error) { - if (*decim_x == *decim_y) { - *decim_x = min_factor; - ++*decim_y; - } else { - swap(*decim_x, *decim_y); - if (*decim_x < *decim_y) - ++*decim_x; - } - } + if (error) + ++*decim_y; } while (*decim_x <= *x_predecim && *decim_y <= *y_predecim && error); if (error) { |