Re: [PATCH 1/4] OMAPDSS: Fix DSS clock multiplier issue on 3703 and probably 3630
From: Tony Lindgren <tony@atomide.com>
Date: 2014-05-08 23:20:07
Also in:
linux-arm-kernel, linux-fbdev, linux-omap
* Tony Lindgren [off-list ref] [140429 16:53]:
Otherwise we can get often errors like the following and the display won't come on: omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay omapdss APPLY error: SYNC_LOST on channel lcd, restarting the output with video overlays disabled There are some earlier references to this issue: http://www.spinics.net/lists/linux-omap/msg59511.html http://www.spinics.net/lists/linux-omap/msg59724.html It seems that it's safe to set the lower values even for 3630. If we can confirm that 3630 works with the higher values reliably we can add further detection.
BTW, I'm also seeing this warning on 3730-evm it may be related: [ 3.523101] ------------[ cut here ]------------ [ 3.528015] WARNING: CPU: 0 PID: 6 at drivers/video/fbdev/omap2/dss/dss.c:483 dss_set_fck_rate+0x6c/0x8c() [ 3.538360] clk rate mismatch: 108000000 != 115200000 [ 3.543518] Modules linked in: [ 3.546966] CPU: 0 PID: 6 Comm: kworker/u2:0 Tainted: G W 3.15.0-rc3-00015-gaa296fa-dirty #391 [ 3.557159] Workqueue: deferwq deferred_probe_work_func [ 3.562774] [<c0014cbc>] (unwind_backtrace) from [<c001191c>] (show_stack+0x10/0x14) [ 3.571014] [<c001191c>] (show_stack) from [<c05660b4>] (dump_stack+0x80/0x9c) [ 3.578704] [<c05660b4>] (dump_stack) from [<c003f558>] (warn_slowpath_common+0x68/0x8c) [ 3.587249] [<c003f558>] (warn_slowpath_common) from [<c003f610>] (warn_slowpath_fmt+0x30/0x40) [ 3.596496] [<c003f610>] (warn_slowpath_fmt) from [<c03129f0>] (dss_set_fck_rate+0x6c/0x8c) [ 3.605407] [<c03129f0>] (dss_set_fck_rate) from [<c0323728>] (dpi_display_enable+0x23c/0x2e4) [ 3.614562] [<c0323728>] (dpi_display_enable) from [<c03323a8>] (sharp_ls_enable+0x58/0xc4) [ 3.623474] [<c03323a8>] (sharp_ls_enable) from [<c0335ee0>] (omapfb_probe+0x548/0x848) [ 3.631988] [<c0335ee0>] (omapfb_probe) from [<c0378cfc>] (platform_drv_probe+0x18/0x48) [ 3.640594] [<c0378cfc>] (platform_drv_probe) from [<c0377938>] (driver_probe_device+0x110/0x22c) [ 3.650024] [<c0377938>] (driver_probe_device) from [<c0376038>] (bus_for_each_drv+0x44/0x8c) [ 3.659088] [<c0376038>] (bus_for_each_drv) from [<c03777f0>] (device_attach+0x74/0x8c) [ 3.667541] [<c03777f0>] (device_attach) from [<c0376ecc>] (bus_probe_device+0x88/0xb0) [ 3.676025] [<c0376ecc>] (bus_probe_device) from [<c03772d0>] (deferred_probe_work_func+0x64/0x94) [ 3.685546] [<c03772d0>] (deferred_probe_work_func) from [<c0057220>] (process_one_work+0x1b4/0x4bc) [ 3.695251] [<c0057220>] (process_one_work) from [<c0057908>] (worker_thread+0x11c/0x398) [ 3.704620] [<c0057908>] (worker_thread) from [<c005df10>] (kthread+0xc8/0xe4) [ 3.712280] [<c005df10>] (kthread) from [<c000e768>] (ret_from_fork+0x14/0x2c) [ 3.719909] ---[ end trace 1c9526c1a2975498 ]---
quoted hunk ↗ jump to hunk
Signed-off-by: Tony Lindgren <tony@atomide.com> --- drivers/video/fbdev/omap2/dss/dss.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/video/fbdev/omap2/dss/dss.c b/drivers/video/fbdev/omap2/dss/dss.c index d55266c..ad6561f 100644 --- a/drivers/video/fbdev/omap2/dss/dss.c +++ b/drivers/video/fbdev/omap2/dss/dss.c@@ -707,9 +707,10 @@ static const struct dss_features omap34xx_dss_feats __initconst = { .dpi_select_source = &dss_dpi_select_source_omap2_omap3, }; +/* Supposedly 3630 can use div 32 mult 2, but that needs to be rechecked */ static const struct dss_features omap3630_dss_feats __initconst = { - .fck_div_max = 32, - .dss_fck_multiplier = 1, + .fck_div_max = 16, + .dss_fck_multiplier = 2, .parent_clk_name = "dpll4_ck", .dpi_select_source = &dss_dpi_select_source_omap2_omap3, };-- 1.8.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html