Qualcomm SPMI PMICs multi-function device bindings
The Qualcomm SPMI series presently includes PM8941, PM8841 and PMA8084
PMICs. These PMICs use a QPNP scheme through SPMI interface.
QPNP is effectively a partitioning scheme for dividing the SPMI extended
register space up into logical pieces, and set of fixed register
locations/definitions within these regions, with some of these regions
specifically used for interrupt handling.
The QPNP PMICs are used with the Qualcomm Snapdragon series SoCs, and are
interfaced to the chip via the SPMI (System Power Management Interface) bus.
Support for multiple independent functions are implemented by splitting the
16-bit SPMI slave address space into 256 smaller fixed-size regions, 256 bytes
each. A function can consume one or more of these fixed-size register regions.
Required properties:
- compatible: Should contain one of:
"qcom,pm8941",
"qcom,pm8841",
"qcom,pma8084",
"qcom,pm8019",
"qcom,pm8226",
"qcom,pm8110",
"qcom,pma8084",
"qcom,pmi8962",
"qcom,pmd9635",
"qcom,pm8994",
"qcom,pmi8994",
"qcom,pm8916",
"qcom,pm8004",
"qcom,pm8909",
or generalized "qcom,spmi-pmic".
- reg: Specifies the SPMI USID slave address for this device.
For more information see:
Documentation/devicetree/bindings/spmi/spmi.txt
Required properties for peripheral child nodes:
- compatible: Should contain "qcom,xxx", where "xxx" is a peripheral name.
Optional properties for peripheral child nodes:
- interrupts: Interrupts are specified as a 4-tuple. For more information
see:
Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt
- interrupt-names: Corresponding interrupt name to the interrupts property
Each child node of SPMI slave id represents a function of the PMIC. In the
example below the rtc device node represents a peripheral of pm8941
SID = 0. The regulator device node represents a peripheral of pm8941 SID = 1.
Example:
spmi {
compatible = "qcom,spmi-pmic-arb";
pm8941@0 {
compatible = "qcom,pm8941", "qcom,spmi-pmic";
reg = <0x0 SPMI_USID>;
rtc {
compatible = "qcom,rtc";
interrupts = <0x0 0x61 0x1 IRQ_TYPE_EDGE_RISING>;
interrupt-names = "alarm";
};
};
pm8941@1 {
compatible = "qcom,pm8941", "qcom,spmi-pmic";
reg = <0x1 SPMI_USID>;
regulator {
compatible = "qcom,regulator";
regulator-name = "8941_boost";
};
};
};
ze='10' name='q' value=''/>
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.
It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server. The call chains were different:
- VT ioctl(KDSETMODE, KD_TEXT):
intel_cleanup_plane_fb+0x5b/0xa0 [i915]
drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
intel_atomic_commit_tail+0x749/0xfe0 [i915]
intel_atomic_commit+0x3cb/0x4f0 [i915]
drm_atomic_commit+0x4b/0x50 [drm]
restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
intel_fbdev_set_par+0x18/0x70 [i915]
fb_set_var+0x236/0x460
fbcon_blank+0x30f/0x350
do_unblank_screen+0xd2/0x1a0
vt_ioctl+0x507/0x12a0
tty_ioctl+0x355/0xc30
do_vfs_ioctl+0xa3/0x5e0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x13/0x94
- i915 unpin_work workqueue:
intel_unpin_work_fn+0x58/0x140 [i915]
process_one_work+0x1f1/0x480
worker_thread+0x48/0x4d0
kthread+0x101/0x140
and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.
Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.
[ Reported it originally to the i915 developers on Jan 8, applying the
ugly workaround on my own now after triggering the problem for the
second time with no feedback.
This is likely to be the same bug reported as
https://bugs.freedesktop.org/show_bug.cgi?id=98829
https://bugs.freedesktop.org/show_bug.cgi?id=99134
which has a patch for the underlying problem, but it hasn't gotten to
me, so I'm applying the workaround. ]
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>