On Mon, Oct 29, 2018 at 07:56:27PM +0530, Jagan Teki wrote:
On Mon, Oct 29, 2018 at 2:52 PM Maxime Ripard maxime.ripard@bootlin.com wrote:
On Fri, Oct 26, 2018 at 08:13:31PM +0530, Jagan Teki wrote:
Add 10 bytes packet overhead for hblk where blank is set using a blanking packet like (4 bytes + 4 bytes + payload + 2 bytes)
This is according to BSP code from BPI-M64-bsp (in drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) dsi_hblk = (ht-hspw)*dsi_pixel_bits[format]/8-(4+4+2);
So, add 10 bytes packet overhead for DSI hblk.
Tested on 2-lane, 4-lane MIPI-DSI LCD panels.
Signed-off-by: Jagan Teki jagan@amarulasolutions.com Tested-by: Jagan Teki jagan@amarulasolutions.com
Changes for v3:
- new patch
Changes for v2:
- none
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 596e560263bf..cf42be1f1ba1 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -461,7 +461,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, { struct mipi_dsi_device *device = dsi->device; unsigned int Bpp = mipi_dsi_pixel_format_to_bpp(device->format) / 8;
u16 hbp, hfp, hsa, hblk, vblk;
u16 hbp, hfp, hsa, hblk_max, hblk, vblk; size_t bytes; u8 *buffer;@@ -494,8 +494,13 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
/* * hblk seems to be the line + porches length.
* The blank is set using a blanking packet (4 bytes + 4 bytes +* payload + 2 bytes). So minimal size is 10 bytes */
hblk = (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp;+#define HBLK_PACKET_OVERHEAD 10
hblk_max = (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp;hblk_max -= HBLK_PACKET_OVERHEAD;hblk = max((unsigned int)HBLK_PACKET_OVERHEAD, hblk_max);I'd rather use the same convention than the other assignments done before in that function.
Yes, old code did use hsa. but it's added 10 bytes packet head instead of subtracting it.
hblk = mode->htotal * Bpp - hsa; => mode->htotal * Bpp - (mode->hsync_end - mode->hsync_start) * Bpp - HSA_PACKET_OVERHEAD); => (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp + HSA_PACKET_OVERHEAD;
And it should be (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp - HSA_PACKET_OVERHEAD;
This patch is simply doing the same by explicitly adding packet over ahead macro, which again used in hfp.
That's not my point.
The rest of the driver uses a construct that would be:
hblk = max((unsigned int)HBLK_PACKET_OVERHEAD, (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp - HBLK_PACKET_OVERHEAD);
We want to remain consistent.
Maxime