Hi,
Dne petek, 09. marec 2018 ob 01:44:55 CET je Ondřej Jirman napisal(a):
Hi,
I've debugged this further and it seems that the code has incorrect assumptions. See docs for mode_set_nofb.
https://elixir.bootlin.com/linux/v4.16-rc4/source/include/drm/drm_modeset_he lper_vtables.h#L209
Does this happen with https://github.com/jernejsk/linux-1/tree/h3_hdmi_v3 ?
I also tested running X, but I don't remember having the issue.
I've added traces to a few functions that call clk_.*exclusive.*() functions, and I see this after a few restarts of Xorg server:
[ 0.783842] *** sun4i_tcon1_mode_set() [ 0.783886] *** sun4i_tcon_channel_set_status(..., 1, true) [ 6.881690] *** sun4i_tcon_channel_set_status(..., 1, false) [ 6.881758] *** sun4i_tcon_channel_set_status(..., 1, true) [ 52.335085] *** sun4i_tcon_channel_set_status(..., 1, false) [ 52.335343] *** sun4i_tcon_channel_set_status(..., 1, true) [ 68.921079] *** sun4i_tcon_channel_set_status(..., 1, false) [ 68.921337] *** sun4i_tcon_channel_set_status(..., 1, true)
mode_set_nofb is called just once, yet sun4i_tcon_channel_set_status(..., 1, false) is called multiple times, which leads to unbalanced calls to clk_set_rate_exclusive and clk_rate_exclusive_put.
I don't know how to fix this.
Since there is no function to check if clock is protected, flag can be introduced within TCON which is set when clock rate is protected and unset when it is unprotected. That way we could track if clk_rate_exclusive_put() needs to be called or not.
Best regards, Jernej
regards, o.
On Fri, Mar 09, 2018 at 01:13:14AM +0100, 'Ondřej Jirman' via linux-sunxi
wrote:
Hi Jernej,
On Thu, Mar 08, 2018 at 11:57:40PM +0100, Jernej Škrabec wrote:
Hi,
Dne četrtek, 08. marec 2018 ob 23:47:17 CET je Ondřej Jirman napisal(a):
Hi,
On Thu, Mar 01, 2018 at 10:34:32PM +0100, Jernej Skrabec wrote:
Currently exclusive TCON clock lock is never released, which, for example, prevents changing resolution on HDMI.
In order to fix that, release clock when disabling TCON. TCON is always disabled first before new mode is set.
Signed-off-by: Jernej Skrabec jernej.skrabec@siol.net
drivers/gpu/drm/sun4i/sun4i_tcon.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 1d714c06ec9d..7f6c4125c89f 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -102,10 +102,12 @@ static void sun4i_tcon_channel_set_status(struct sun4i_tcon *tcon, int channel,>
return;}
- if (enabled)
if (enabled) {
clk_prepare_enable(clk);
- else
} else {
clk_rate_exclusive_put(clk);clk_disable_unprepare(clk);
}
}
At least in the linux-next/master I can't see clk_rate_exclusive_get
call:
It is in drm-misc/drm-misc-fixes: https://cgit.freedesktop.org/drm/drm-misc/commit/?h=drm-misc-fixes&id=79 d103a565d16b1893d990b2ee5e0fe71767759f
My patch is also applied in same branch, so there should be no issues while merging all those branches.
linux-next doesn't have either patches currently: https://git.kernel.org/pub/ scm/linux/kernel/git/next/linux-next.git/log/drivers/gpu/drm/sun4i
This is issue only if you manually apply one patch without the other.
I have (and had) both patches applied. There's perhaps some code path, where sun4i_tcon_channel_set_status(..., false) is called in unbalanced way with regards to clk_set_rate_exclusive().
The issue occurs when starting Xorg. But Xorg works fine.
regards,
o.
Best regards, Jernej
$ git grep 'exclusive' linux-next/master -- drivers/gpu/drm/sun4i
linux-next/master:sun4i_hdmi.h: * On sun5i the threshold is exclusive, i.e. does not include, linux-next/master:sun4i_tcon.c: clk_rate_exclusive_put(clk); linux-next/master:sun4i_tcon.c: clk_set_rate_exclusive(tcon->dclk, mode->crtc_clock * 1000); linux-next/master:sun4i_tcon.c: clk_set_rate_exclusive(tcon->sclk1, mode->crtc_clock * 1000);
and the kernel complains too:
[ 841.915161] ------------[ cut here ]------------ [ 841.915187] WARNING: CPU: 0 PID: 273 at /workspace/megous.com/orangepi-pc/linux-4.16/drivers/clk/clk.c:608 clk_rate_exclusive_put+0x48/0x4c [ 841.915194] CPU: 0 PID: 273 Comm: Xorg Not tainted 4.16.0-rc4-00268-gbac2ecf73ed0 #13 [ 841.915196] Hardware name: Allwinner sun8i Family [ 841.915217] [<c0228440>] (unwind_backtrace) from [<c0225b90>] (show_stack+0x10/0x14) [ 841.915228] [<c0225b90>] (show_stack) from [<c0b094bc>] (dump_stack+0x88/0x9c) [ 841.915237] [<c0b094bc>] (dump_stack) from [<c0240294>] (__warn+0xd4/0xf0) [ 841.915244] [<c0240294>] (__warn) from [<c0240380>] (warn_slowpath_null+0x40/0x48) [ 841.915250] [<c0240380>] (warn_slowpath_null) from [<c0619b6c>] (clk_rate_exclusive_put+0x48/0x4c) [ 841.915261] [<c0619b6c>] (clk_rate_exclusive_put) from [<c0694624>] (sun4i_tcon_set_status+0x178/0x2f0) [ 841.915269] [<c0694624>] (sun4i_tcon_set_status) from [<c06930c0>] (sun4i_crtc_atomic_disable+0x7c/0xe4) [ 841.915279] [<c06930c0>] (sun4i_crtc_atomic_disable) from [<c06637fc>] (drm_atomic_helper_commit_modeset_disables+0x390/0x46c) [ 841.915288] [<c06637fc>] (drm_atomic_helper_commit_modeset_disables) from [<c0664df4>] (drm_atomic_helper_commit_tail_rpm+0x18/0x64) [ 841.915295] [<c0664df4>] (drm_atomic_helper_commit_tail_rpm) from [<c0664da8>] (commit_tail+0x40/0x6c) [ 841.915302] [<c0664da8>] (commit_tail) from [<c06652b0>] (drm_atomic_helper_commit+0xbc/0x128) [ 841.915311] [<c06652b0>] (drm_atomic_helper_commit) from [<c0668d40>] (restore_fbdev_mode_atomic+0x100/0x1fc) [ 841.915319] [<c0668d40>] (restore_fbdev_mode_atomic) from [<c0668f1c>] (drm_fb_helper_dpms+0x50/0x130) [ 841.915328] [<c0668f1c>] (drm_fb_helper_dpms) from [<c0669e9c>] (drm_fb_helper_blank+0x54/0x90) [ 841.915337] [<c0669e9c>] (drm_fb_helper_blank) from [<c06088cc>] (fb_blank+0x54/0xa8) [ 841.915343] [<c06088cc>] (fb_blank) from [<c0608c80>] (do_fb_ioctl+0x360/0x62c) [ 841.915351] [<c0608c80>] (do_fb_ioctl) from [<c0362648>] (do_vfs_ioctl+0x9c/0x774) [ 841.915358] [<c0362648>] (do_vfs_ioctl) from [<c0362d54>] (SyS_ioctl+0x34/0x58) [ 841.915364] [<c0362d54>] (SyS_ioctl) from [<c0201120>] (ret_fast_syscall+0x0/0x4c) [ 841.915368] Exception stack(0xe5fc5fa8 to 0xe5fc5ff0) [ 841.915373] 5fa0: 00674f10 00675460 0000000b 00004611 00000001 00000000 [ 841.915379] 5fc0: 00674f10 00675460 00000001 00000036 00650474 00000000 006504a4 00675df8 [ 841.915382] 5fe0: b61a502c be8acb2c b6192c38 b6b152ec [ 841.915386] ---[ end trace fa81b956197707f8 ]---
It looks like clk_rate_exclusive_put inside sun4i_tcon_channel_set_status is called without first calling some function that would call clk_set_rate_exclusive, leading to unbalanced get/put calls.
regards,
o.
static void sun4i_tcon_lvds_set_status(struct sun4i_tcon *tcon,
-- 2.16.2
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