Currently the timer is armed for 1ms after the first use and is killed
immediately, dropping the forcewake as early as possible. However, for
very frequent operations the forcewake dance has a large impact on
latency and keeping the timer alive until we are idle is preferred. To
achieve this, if we call intel_uncore_forcewake_get whilst the timer is
alive (repeated use), then set a flag to restart the timer on expiry
rather than drop the forcewake usage count. The timer is racy, the
consequence of the race is to expire the timer earlier than is now
desired but does not impact on correct behaviour. The offset the race
slightly, we set the active flag again on intel_uncore_forcewake_put.
The effect should be to reduce the jitter of reacquiring the fw every
1ms on a busy system. However, the cost is to keep the timer alive for
an extra 1ms on a nearly idle system. We chose to incur the jitter
previously to keep the timer off for as much as possible.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170526132209.14640-1-chris@chris-wilson.co.uk
ELK seems to very picky about the preconditions to reset.
Evidence on Eaglelake (8086:2e12 (rev 03)) shows that it does
not like if reset occurs when there is active ring.
Ville found out that there is workaround with name
'WaMediaResetMainRingCleanup' which suggests that we need to
cleanup rings before resetting. It is unclear what cleanup
exactly means but evidence shows that stopping the ring
does have an effect on reset reliability. This patch makes
reset successful on hangs induced by chained batches (the igt ones).
Note that if the hang is inside a shader, it is possible
that our attempts to stop the ring achieves anything.
v2: zero ctl,head,tail also. bug ref. use driver debugs (Chris)
v3: specify platform on testcases, comment tidyup (Chris)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100942
Testcase: igt/gem_busy/*-hang #elk
Testcase: igt/gem_ringfill/hang-* #elk
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519091340.21439-1-mika.kuoppala@intel.com
Replace the handcrafter loop when checking for fifo slots
with atomic wait for. This brings this wait in line with
the other waits on register access. We also get a readable
timeout constraint, so make it to fail after 10ms.
Chris suggested that we should fail silently as the fifo debug
handler, now attached to unclaimed mmio handling, will take care of the
possible errors at later stage.
Note that the decision to wait was changed so that we avoid
allocating the first reserved entry. Nor do we reduce the count
if we fail the wait, removing the possiblity to wrap the
count if the hw fifo returned zero.
v2: remove unclaimed check on timeout (Chris)
v3: use void return (Chris)
References: https://bugs.freedesktop.org/show_bug.cgi?id=100247
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1491493182-31540-1-git-send-email-mika.kuoppala@intel.com
Remove the per-mmio checking of the FIFO debug register into the common
conditional mmio debug handling. Based on patch from Chris Wilson.
v2: postpone warn on fifodbg for unclaimed reg debugs
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Looks like intel_guc_reset had the ability to sleep under the
uncore spinlock since forever but it wasn't detected until the
recent changes annotated the wait for register with might_sleep.
I have fixed it by removing holding of the uncore spinlock over
the call to gen6_hw_domain_reset, since I do not see that is
really needed. But there is always a possibility I am missing
some nasty detail so please double check.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Acked-by: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Baytrail PMIC vs. PMU race fixes from Hans de Goede
This time the right version (v4), with the compile fix.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Listen for PMIC bus access notifications and get FORCEWAKE_ALL while
the bus is accessed to avoid needing to do any forcewakes, which need
PMIC bus access, while the PMIC bus is busy:
This fixes errors like these showing up in dmesg, usually followed
by a gfx or system freeze:
[drm:fw_domains_get [i915]] *ERROR* render: timed out waiting for forcewake ack request.
[drm:fw_domains_get [i915]] *MEDIA* render: timed out waiting for forcewake ack request.
i2c_designware 808622C1:06: punit semaphore timed out, resetting
i2c_designware 808622C1:06: PUNIT SEM: 2
i2c_designware 808622C1:06: couldn't acquire bus ownership
Downside of this approach is that it causes wakeups whenever the PMIC
bus is accessed. Unfortunately we cannot simply wait for the PMIC bus
to go idle when we hit a race, as forcewakes may be done from interrupt
handlers where we cannot sleep to wait for the i2c PMIC bus access to
finish.
Note that the notifications and thus the wakeups will only happen on
baytrail / cherrytrail devices using PMICs with a shared i2c bus for
P-Unit and host PMIC access (i2c busses with a _SEM method in their
APCI node), e.g. an axp288 PMIC.
I plan to write some patches for drivers accessing the PMIC bus to
limit their bus accesses to a bare minimum (e.g. cache registers, do not
update battery level more often then 4 times a minute), to limit the
amount of wakeups.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Wiggle in conflicts.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Backmerge Linux 4.10-rc2 to resync with our -fixes cherry-picks. I've
done the backmerge directly because Dave is on vacation.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
A bunch of source files with just a few instances of the
incorrect INTEL_INFO use.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Decoupled MMIO is an alternative way to access forcewake domain
registers, which requires less cycles for a single read/write and
avoids frequent software forcewake.
This certainly gives advantage over the forcewake as this new
mechanism “decouples” CPU cycles and allow them to complete even
when GT is in a CPD (frequency change) or C6 state.
This can co-exist with forcewake and we will continue to use forcewake
as appropriate. E.g. 64-bit register writes to avoid writing 2 dwords
separately and land into funny situations.
v2:
- Moved platform check out of the function and got rid of duplicate
functions to find out decoupled power domain (Chris)
- Added a check for forcewake already held and skipped decoupled
access (Chris)
- Skipped writing 64 bit registers through decoupled MMIO (Chris)
v3:
- Improved commit message with more info on decoupled mmio (Tvrtko)
- Changed decoupled operation to enum and used u32 instead of
uint_32 data type for register offset (Tvrtko)
- Moved HAS_DECOUPLED_MMIO to device info (Tvrtko)
- Added lookup table for converting fw_engine to pd_engine (Tvrtko)
- Improved __gen9_decoupled_read and __gen9_decoupled_write
routines (Tvrtko)
v4:
- Fixed alignment and variable names (Chris)
- Write GEN9_DECOUPLED_REG0_DW1 register in just one go (Zhe Wang)
v5:
- Changed HAS_DECOUPLED_MMIO() argument name to dev_priv (Tvrtko)
- Sanitize info->had_decoupled_mmio at init (Chris)
Signed-off-by: Zhe Wang <zhe1.wang@intel.com>
Signed-off-by: Praveen Paneri <praveen.paneri@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479230360-22395-1-git-send-email-praveen.paneri@intel.com
Simply replace the linear search with the kernel's binary
search implementation. There is only six registers currently
in that table so this may not be that interesting. It adds a
function call so hopefully remains performance neutral for now.
v2: No need for manual conversion to bool for return.
(Joonas Lahtinen)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Also verify the order at runtime. This was we can start using
binary search on it in a following patch.
v2: Add comment on the sorted array and only check it when
debug option is enabled.
v3: Use IS_ENABLED. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v1)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
We notice two identical copies of the shadow register table and
following from that removal can also unify CHV and Gen9 write
mmio functions and macros into a single implementation.
v2: Name fwtable consistently and use HAS_FWTABLE. (Joonas Lahtinen)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
It is now obvious VLV, CHV and Gen9 mmio read fcuntions are
completely identical so we can remove the three copies and
just keep the newly named generic implementation.
v2: Use fwtable naming consistently. (Joonas Lahtinen)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Remove some macros which are now obviously identical.
v2: Added HAS_FWTABLE macro and simplified intel_uncore_forcewake_for_read.
(Joonas Lahtinen)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
