| Message ID | 20250213221702.606-1-linux@martijnvandeventer.nl (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Neil Armstrong |
| Headers | show |
| Series | clk: meson: g12a: Fix kernel warnings when no display attached | expand |
On Thu 13 Feb 2025 at 23:17, Martijn van Deventer <linux@martijnvandeventer.nl> wrote: > When booting SM1 or G12A boards without a dislay attached to HDMI, > the kernel shows the following warning: > > [CRTC:46:meson_crtc] vblank wait timed out > WARNING: CPU: 2 PID: 265 at drivers/gpu/drm/drm_atomic_helper.c:1682 drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > CPU: 2 UID: 0 PID: 265 Comm: setfont Tainted: G C > Tainted: [C]=CRAP > pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > lr : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > Call trace: > drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > drm_atomic_helper_commit_tail_rpm+0x84/0xa0 > commit_tail+0xa4/0x18c > drm_atomic_helper_commit+0x164/0x178 > drm_atomic_commit+0xb4/0xec > drm_client_modeset_commit_atomic+0x210/0x270 > drm_client_modeset_commit_locked+0x5c/0x188 > drm_fb_helper_pan_display+0xb8/0x1d4 > fb_pan_display+0x7c/0x120 > bit_update_start+0x20/0x48 > fbcon_switch+0x418/0x54c > el0t_64_sync+0x194/0x198 > > This happens when the kernel disables the unused clocks. > Sometimes this causes the boot to hang. > > By (re)adding the flag CLK_IGNORE_UNUSED to the VCLK2 clocks, these > clocks will not be disabled. > > This partially reverts commit b70cb1a21a54 ("clk: meson: g12a: > make VCLK2 and ENCL clock path configurable by CCF"). It looks like DRM needs those clock enabled regardless of connection status on HDMI. Even with this change applied, you would get the same problem again if the bootloader does not take of turning the clock on, which is not a given. CLK_IGNORE_UNUSED gives not guarantee a clock will be enabled or stay enabled at any point. A proper fix to this issue should be done in DRM, IMO. > > Fixes: b70cb1a21a54 ("clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"). > Signed-off-by: Martijn van Deventer <linux@martijnvandeventer.nl> > --- > drivers/clk/meson/g12a.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c > index cfffd434e998..1651898658f5 100644 > --- a/drivers/clk/meson/g12a.c > +++ b/drivers/clk/meson/g12a.c > @@ -3234,7 +3234,7 @@ static struct clk_regmap g12a_vclk2_div = { > &g12a_vclk2_input.hw > }, > .num_parents = 1, > - .flags = CLK_SET_RATE_GATE, > + .flags = CLK_SET_RATE_GATE | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3270,7 +3270,7 @@ static struct clk_regmap g12a_vclk2 = { > .ops = &meson_vclk_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2_div.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3354,7 +3354,7 @@ static struct clk_regmap g12a_vclk2_div1 = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3368,7 +3368,7 @@ static struct clk_regmap g12a_vclk2_div2_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3382,7 +3382,7 @@ static struct clk_regmap g12a_vclk2_div4_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3396,7 +3396,7 @@ static struct clk_regmap g12a_vclk2_div6_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > };
On 13/02/2025 23:17, Martijn van Deventer wrote: > When booting SM1 or G12A boards without a dislay attached to HDMI, > the kernel shows the following warning: > > [CRTC:46:meson_crtc] vblank wait timed out > WARNING: CPU: 2 PID: 265 at drivers/gpu/drm/drm_atomic_helper.c:1682 drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > CPU: 2 UID: 0 PID: 265 Comm: setfont Tainted: G C > Tainted: [C]=CRAP > pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > lr : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > Call trace: > drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 > drm_atomic_helper_commit_tail_rpm+0x84/0xa0 > commit_tail+0xa4/0x18c > drm_atomic_helper_commit+0x164/0x178 > drm_atomic_commit+0xb4/0xec > drm_client_modeset_commit_atomic+0x210/0x270 > drm_client_modeset_commit_locked+0x5c/0x188 > drm_fb_helper_pan_display+0xb8/0x1d4 > fb_pan_display+0x7c/0x120 > bit_update_start+0x20/0x48 > fbcon_switch+0x418/0x54c > el0t_64_sync+0x194/0x198 > > This happens when the kernel disables the unused clocks. > Sometimes this causes the boot to hang. > > By (re)adding the flag CLK_IGNORE_UNUSED to the VCLK2 clocks, these > clocks will not be disabled. > > This partially reverts commit b70cb1a21a54 ("clk: meson: g12a: > make VCLK2 and ENCL clock path configurable by CCF"). > > Fixes: b70cb1a21a54 ("clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"). > Signed-off-by: Martijn van Deventer <linux@martijnvandeventer.nl> > --- > drivers/clk/meson/g12a.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c > index cfffd434e998..1651898658f5 100644 > --- a/drivers/clk/meson/g12a.c > +++ b/drivers/clk/meson/g12a.c > @@ -3234,7 +3234,7 @@ static struct clk_regmap g12a_vclk2_div = { > &g12a_vclk2_input.hw > }, > .num_parents = 1, > - .flags = CLK_SET_RATE_GATE, > + .flags = CLK_SET_RATE_GATE | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3270,7 +3270,7 @@ static struct clk_regmap g12a_vclk2 = { > .ops = &meson_vclk_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2_div.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3354,7 +3354,7 @@ static struct clk_regmap g12a_vclk2_div1 = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3368,7 +3368,7 @@ static struct clk_regmap g12a_vclk2_div2_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3382,7 +3382,7 @@ static struct clk_regmap g12a_vclk2_div4_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > > @@ -3396,7 +3396,7 @@ static struct clk_regmap g12a_vclk2_div6_en = { > .ops = &clk_regmap_gate_ops, > .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, > .num_parents = 1, > - .flags = CLK_SET_RATE_PARENT, > + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, > }, > }; > Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c index cfffd434e998..1651898658f5 100644 --- a/drivers/clk/meson/g12a.c +++ b/drivers/clk/meson/g12a.c @@ -3234,7 +3234,7 @@ static struct clk_regmap g12a_vclk2_div = { &g12a_vclk2_input.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_GATE, + .flags = CLK_SET_RATE_GATE | CLK_IGNORE_UNUSED, }, }; @@ -3270,7 +3270,7 @@ static struct clk_regmap g12a_vclk2 = { .ops = &meson_vclk_gate_ops, .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2_div.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, }, }; @@ -3354,7 +3354,7 @@ static struct clk_regmap g12a_vclk2_div1 = { .ops = &clk_regmap_gate_ops, .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, }, }; @@ -3368,7 +3368,7 @@ static struct clk_regmap g12a_vclk2_div2_en = { .ops = &clk_regmap_gate_ops, .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, }, }; @@ -3382,7 +3382,7 @@ static struct clk_regmap g12a_vclk2_div4_en = { .ops = &clk_regmap_gate_ops, .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, }, }; @@ -3396,7 +3396,7 @@ static struct clk_regmap g12a_vclk2_div6_en = { .ops = &clk_regmap_gate_ops, .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, }, };
When booting SM1 or G12A boards without a dislay attached to HDMI, the kernel shows the following warning: [CRTC:46:meson_crtc] vblank wait timed out WARNING: CPU: 2 PID: 265 at drivers/gpu/drm/drm_atomic_helper.c:1682 drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 CPU: 2 UID: 0 PID: 265 Comm: setfont Tainted: G C Tainted: [C]=CRAP pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 lr : drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 Call trace: drm_atomic_helper_wait_for_vblanks.part.0+0x240/0x264 drm_atomic_helper_commit_tail_rpm+0x84/0xa0 commit_tail+0xa4/0x18c drm_atomic_helper_commit+0x164/0x178 drm_atomic_commit+0xb4/0xec drm_client_modeset_commit_atomic+0x210/0x270 drm_client_modeset_commit_locked+0x5c/0x188 drm_fb_helper_pan_display+0xb8/0x1d4 fb_pan_display+0x7c/0x120 bit_update_start+0x20/0x48 fbcon_switch+0x418/0x54c el0t_64_sync+0x194/0x198 This happens when the kernel disables the unused clocks. Sometimes this causes the boot to hang. By (re)adding the flag CLK_IGNORE_UNUSED to the VCLK2 clocks, these clocks will not be disabled. This partially reverts commit b70cb1a21a54 ("clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"). Fixes: b70cb1a21a54 ("clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"). Signed-off-by: Martijn van Deventer <linux@martijnvandeventer.nl> --- drivers/clk/meson/g12a.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)