diff options
| author | Dom Cobley <popcornmix@gmail.com> | 2024-06-21 16:20:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-05 14:01:36 +0100 |
| commit | 74f21be9990a42dc2357bcf87a13e16c6998b90e (patch) | |
| tree | 86ac51a989b6e703bb7556ca32e27b90c2b698c2 | |
| parent | 8d4cd940d592455b2975888d652322ff2a0a889f (diff) | |
drm/vc4: hdmi: Avoid hang with debug registers when suspended
[ Upstream commit 223ee2567a55e4f80315c768d2969e6a3b9fb23d ]
Trying to read /sys/kernel/debug/dri/1/hdmi1_regs
when the hdmi is disconnected results in a fatal system hang.
This is due to the pm suspend code disabling the dvp clock.
That is just a gate of the 108MHz clock in DVP_HT_RPI_MISC_CONFIG,
which results in accesses hanging AXI bus.
Protect against this.
Fixes: 25eb441d55d4 ("drm/vc4: hdmi: Add all the vc5 HDMI registers into the debugfs dumps")
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-17-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hdmi.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 6611ab7c26a6..6c2215068c53 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -147,6 +147,8 @@ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused) if (!drm_dev_enter(drm, &idx)) return -ENODEV; + WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev)); + drm_print_regset32(&p, &vc4_hdmi->hdmi_regset); drm_print_regset32(&p, &vc4_hdmi->hd_regset); drm_print_regset32(&p, &vc4_hdmi->cec_regset); @@ -156,6 +158,8 @@ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused) drm_print_regset32(&p, &vc4_hdmi->ram_regset); drm_print_regset32(&p, &vc4_hdmi->rm_regset); + pm_runtime_put(&vc4_hdmi->pdev->dev); + drm_dev_exit(idx); return 0; |