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authorDave Airlie <airlied@redhat.com>2022-10-21 08:08:25 +1000
committerDave Airlie <airlied@redhat.com>2022-10-21 08:08:30 +1000
commit8865dd756f92e6745cac64f4dd50e4dc3b9864cc (patch)
tree0ee1b346ec597c227a0af2512176cb517d593614
parent9abf2313adc1ca1b6180c508c25f22f9395cc780 (diff)
parent4190e8bbcbc77a9c36724681801cedc5229e7fc2 (diff)
Merge tag 'drm-misc-fixes-2022-10-13' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
Short summary of fixes pull: * vc4: HDMI fixes Signed-off-by: Dave Airlie <airlied@redhat.com> From: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/Y0gGdlujszCstDeP@linux-uq9g
-rw-r--r--drivers/gpu/drm/vc4/vc4_drv.c1
-rw-r--r--drivers/gpu/drm/vc4/vc4_hdmi.c29
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index ffbbb454c9e8..2027063fdc30 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -490,6 +490,7 @@ module_init(vc4_drm_register);
module_exit(vc4_drm_unregister);
MODULE_ALIAS("platform:vc4-drm");
+MODULE_SOFTDEP("pre: snd-soc-hdmi-codec");
MODULE_DESCRIPTION("Broadcom VC4 DRM Driver");
MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 64f9feabf43e..596e311d6e58 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -3318,12 +3318,37 @@ static int vc4_hdmi_runtime_resume(struct device *dev)
struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
unsigned long __maybe_unused flags;
u32 __maybe_unused value;
+ unsigned long rate;
int ret;
+ /*
+ * The HSM clock is in the HDMI power domain, so we need to set
+ * its frequency while the power domain is active so that it
+ * keeps its rate.
+ */
+ ret = clk_set_min_rate(vc4_hdmi->hsm_clock, HSM_MIN_CLOCK_FREQ);
+ if (ret)
+ return ret;
+
ret = clk_prepare_enable(vc4_hdmi->hsm_clock);
if (ret)
return ret;
+ /*
+ * Whenever the RaspberryPi boots without an HDMI monitor
+ * plugged in, the firmware won't have initialized the HSM clock
+ * rate and it will be reported as 0.
+ *
+ * If we try to access a register of the controller in such a
+ * case, it will lead to a silent CPU stall. Let's make sure we
+ * prevent such a case.
+ */
+ rate = clk_get_rate(vc4_hdmi->hsm_clock);
+ if (!rate) {
+ ret = -EINVAL;
+ goto err_disable_clk;
+ }
+
if (vc4_hdmi->variant->reset)
vc4_hdmi->variant->reset(vc4_hdmi);
@@ -3345,6 +3370,10 @@ static int vc4_hdmi_runtime_resume(struct device *dev)
#endif
return 0;
+
+err_disable_clk:
+ clk_disable_unprepare(vc4_hdmi->hsm_clock);
+ return ret;
}
static void vc4_hdmi_put_ddc_device(void *ptr)