[PATCH] drm/i915: Add NO_VLV_DISP_PW_DPIO_CMN_BC_INIT quirk
Hans de Goede
hdegoede at redhat.com
Sun Oct 24 15:50:10 UTC 2021
Add a NO_VLV_DISP_PW_DPIO_CMN_BC_INIT quirk to fix i915 not working on
the Xiaomi Mi Pad 2 (with CHT x5-Z8500 SoC).
The Xiaomi Mi Pad 2 uses quite an unusual hardware-design for a Cherry
Trail tablet. It deviates from the typical reference design based tablets
in many ways.
The Mi Pad 2 does not have any DisplayPort or HDMI outouts. I suspect that
as part of its unusual design it also has some supply rail which is only
used for DisplayPort or HDMI not connected.
Force-enabling the dpio-common-bc powerwell as the i915 normal does at boot
appears to cause the P-Unit to hang. When booting with a serial-usb console
the following errors are logged before the system freezes:
i915 0000:00:02.0: [drm] *ERROR* timeout setting power well state 00000000 (fffff3ff)
i915 0000:00:02.0: [drm] *ERROR* Display PHY 0 is not power up
------------[ cut here ]------------
i915 0000:00:02.0: DPIO read pipe A reg 0x8170 == 0xffffffff
WARNING: CPU: 3 PID: 258 at drivers/gpu/drm/i915/intel_sideband.c:257 vlv_dpio_read+0x95/0xb0 [i915]
...
Call Trace:
chv_dpio_cmn_power_well_enable+0xab/0x210 [i915]
__intel_display_power_get_domain.part.0+0xa0/0xc0 [i915]
intel_power_domains_init_hw+0x26d/0x760 [i915]
intel_modeset_init_noirq+0x5d/0x270 [i915]
i915_driver_probe+0x6b6/0xd10 [i915]
...
If I disable the WARN about the register being 0xffffffff, so that the
system can log some more dmesg output over the serial console before
freezing, the following errors are also logged:
i915 0000:00:02.0: [drm] *ERROR* timeout setting power well state 00000000 (fcfff3ff)
i915 0000:00:02.0: [drm] *ERROR* Display PHY 1 is not power up
With this patch to disable the force-enabling of the PHY 0 / dpio-common-bc
powerwell in place, this error for PHY 1 goes away. So it seems that trying
the force-enabling of the PHY 0 / dpio-common-bc powerwell freezes the
P-Unit, causing the subsequent enabling of PHY 1 to also fail (and causing
the entire system to freeze within seconds).
With this patch the PHY 1 error disappears and the entire system works.
Note this change also moves the intel_init_quirks() call a bit up inside
intel_modeset_init_noirq() this is necessary so that the quirk is set
before the intel_power_domains_init_hw() call. This is harmless, all that
intel_init_quirks() does is set some bits in drm_i915_private.quirks and
make some drm_info() log calls.
Reported-by: Tsuchiya Yuto <kitakar at gmail.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
drivers/gpu/drm/i915/display/intel_display.c | 4 ++--
.../gpu/drm/i915/display/intel_display_power.c | 16 ++++++++++++++--
drivers/gpu/drm/i915/display/intel_quirks.c | 10 ++++++++++
drivers/gpu/drm/i915/i915_drv.h | 1 +
4 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 015854b5078c..1fb885cc86c9 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -12467,6 +12467,8 @@ int intel_modeset_init_noirq(struct drm_i915_private *i915)
if (ret)
goto cleanup_bios;
+ intel_init_quirks(i915);
+
/* FIXME: completely on the wrong abstraction layer */
intel_power_domains_init_hw(i915, false);
@@ -12501,8 +12503,6 @@ int intel_modeset_init_noirq(struct drm_i915_private *i915)
INIT_WORK(&i915->atomic_helper.free_work,
intel_atomic_helper_free_state_worker);
- intel_init_quirks(i915);
-
intel_fbc_init(i915);
return 0;
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index cce1a926fcc1..eeaba3dc064b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -2090,8 +2090,14 @@ __intel_display_power_get_domain(struct drm_i915_private *dev_priv,
if (intel_display_power_grab_async_put_ref(dev_priv, domain))
return;
- for_each_power_domain_well(dev_priv, power_well, BIT_ULL(domain))
+ for_each_power_domain_well(dev_priv, power_well, BIT_ULL(domain)) {
+ if (domain == POWER_DOMAIN_INIT &&
+ (dev_priv->quirks & QUIRK_NO_VLV_DISP_PW_DPIO_CMN_BC_INIT) &&
+ power_well->desc->id == VLV_DISP_PW_DPIO_CMN_BC)
+ continue;
+
intel_power_well_get(dev_priv, power_well);
+ }
power_domains->domain_use_count[domain]++;
}
@@ -2184,8 +2190,14 @@ __intel_display_power_put_domain(struct drm_i915_private *dev_priv,
power_domains->domain_use_count[domain]--;
- for_each_power_domain_well_reverse(dev_priv, power_well, BIT_ULL(domain))
+ for_each_power_domain_well_reverse(dev_priv, power_well, BIT_ULL(domain)) {
+ if (domain == POWER_DOMAIN_INIT &&
+ (dev_priv->quirks & QUIRK_NO_VLV_DISP_PW_DPIO_CMN_BC_INIT) &&
+ power_well->desc->id == VLV_DISP_PW_DPIO_CMN_BC)
+ continue;
+
intel_power_well_put(dev_priv, power_well);
+ }
}
static void __intel_display_power_put(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/i915/display/intel_quirks.c
index 8a52b7a16774..c377f515bbf4 100644
--- a/drivers/gpu/drm/i915/display/intel_quirks.c
+++ b/drivers/gpu/drm/i915/display/intel_quirks.c
@@ -59,6 +59,13 @@ static void quirk_no_pps_backlight_power_hook(struct drm_i915_private *i915)
drm_info(&i915->drm, "Applying no pps backlight power quirk\n");
}
+/* The Xiaomi Mi Pad 2 CHT tablet hangs on enabling the dpio-common-bc well */
+static void quirk_no_vlv_disp_pw_dpio_cmn_bc_init(struct drm_i915_private *i915)
+{
+ i915->quirks |= QUIRK_NO_VLV_DISP_PW_DPIO_CMN_BC_INIT;
+ drm_info(&i915->drm, "Applying no dpio-common-bc powerwell init quirk\n");
+}
+
struct intel_quirk {
int device;
int subsystem_vendor;
@@ -190,6 +197,9 @@ static struct intel_quirk intel_quirks[] = {
/* ASRock ITX*/
{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
+
+ /* Xiaomi Mi Pad 2 */
+ { 0x22b0, 0x1d72, 0x1502, quirk_no_vlv_disp_pw_dpio_cmn_bc_init },
};
void intel_init_quirks(struct drm_i915_private *i915)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 005b1cec7007..b907b49b4f0e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -524,6 +524,7 @@ struct i915_drrs {
#define QUIRK_INCREASE_T12_DELAY (1<<6)
#define QUIRK_INCREASE_DDI_DISABLED_TIME (1<<7)
#define QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK (1<<8)
+#define QUIRK_NO_VLV_DISP_PW_DPIO_CMN_BC_INIT (1<<9)
struct intel_fbdev;
struct intel_fbc_work;
--
2.31.1
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