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_helper_vtables.h#L209 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. 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@xxxxxxxx> > > > > --- > > > > > > > > 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=79d103a565d16b1893d990b2ee5e0fe71767759f > > > > 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 > > > > > > > > -- > > > > You received this message because you are subscribed to the Google Groups > > > > "linux-sunxi" group. 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