[Intel-gfx] [PATCH 2/2] drm/i915/gt: preempt and reset based on reset domain
kernel test robot
lkp at intel.com
Wed Mar 16 20:19:05 UTC 2022
Hi Tejas,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm-tip/drm-tip]
[cannot apply to drm-intel/for-linux-next v5.17-rc8 next-20220316]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Tejas-Upadhyay/drm-i915-gt-preempt-engine-to-idle-before-reset/20220316-215054
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: x86_64-randconfig-a005 (https://download.01.org/0day-ci/archive/20220317/202203170430.cDmFRpYE-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a6ec1e3d798f8eab43fb3a91028c6ab04e115fcb)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/06139e9768f3f8e43bf061ae6292feb7daf07944
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Tejas-Upadhyay/drm-i915-gt-preempt-engine-to-idle-before-reset/20220316-215054
git checkout 06139e9768f3f8e43bf061ae6292feb7daf07944
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>
All warnings (new ones prefixed by >>):
>> drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2524:7: warning: variable 'err' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (READ_ONCE(el->pending[0])) {
^~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:47:28: note: expanded from macro 'READ_ONCE'
#define READ_ONCE(x) \
^
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2538:9: note: uninitialized use occurs here
return err;
^~~
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2524:3: note: remove the 'if' if its condition is always true
if (READ_ONCE(el->pending[0])) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2489:6: warning: variable 'err' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (*el->active) { /* preempt to idle required */
^~~~~~~~~~~
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2538:9: note: uninitialized use occurs here
return err;
^~~
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2489:2: note: remove the 'if' if its condition is always true
if (*el->active) { /* preempt to idle required */
^~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gt/intel_execlists_submission.c:2462:9: note: initialize the variable 'err' to silence this warning
int err;
^
= 0
2 warnings generated.
vim +2524 drivers/gpu/drm/i915/gt/intel_execlists_submission.c
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2453
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2454 /* XXX return error and force a full reset if we fail to
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2455 * preempt-to-idle
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2456 */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2457 static int execlists_suspend(struct intel_engine_cs *engine)
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2458 {
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2459 struct i915_sched_engine *se = engine->sched_engine;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2460 struct intel_engine_execlists * const el = &engine->execlists;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2461 unsigned long timeout;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2462 int err;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2463
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2464 if (!intel_engine_pm_get_if_awake(engine))
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2465 return 0;
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2466 ENGINE_TRACE(engine, "supending active engine\n");
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2467 /* Stop further submissions, but listen for our own preempt-to-idle */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2468 tasklet_disable(&se->tasklet);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2469 se->tasklet.callback = suspend_tasklet;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2470 tasklet_enable(&se->tasklet);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2471
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2472 /*
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2473 * We have to wait for the HW to complete a pending context switch
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2474 * before we can write to ELS[PQ] again. Otherwise the behaviour
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2475 * is undefined...
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2476 *
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2477 * If the engine is truly hung, it will neither clear pending
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2478 * nor respond to our preemption request. In the later case,
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2479 * we have the dilemma of how to restore hang detection...
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2480 */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2481 timeout = jiffies + HZ / 2;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2482 while (READ_ONCE(el->pending[0]) && time_before(jiffies, timeout))
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2483 intel_engine_flush_submission(engine);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2484 if (READ_ONCE(el->pending[0])) {
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2485 err = -EBUSY;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2486 goto err;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2487 }
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2488
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2489 if (*el->active) { /* preempt to idle required */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2490 struct i915_request **pending = el->pending;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2491 struct intel_context *ce = el->preempt_context;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2492 u64 desc;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2493 int n;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2494
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2495 /* Always submit an empty / idle context */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2496 desc = lrc_update_regs(ce, engine, ce->ring->tail);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2497
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2498 /*
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2499 * As we submit a dummy context, we will get two events.
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2500 * First a preemption of the running context, causing us
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2501 * to promote el->pending to el->inflight. And then
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2502 * we will receive a completion event as our context
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2503 * idles.
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2504 *
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2505 * We can use any dummy request here for tracking the
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2506 * preemption events.
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2507 */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2508 execlists_schedule_in(*el->active, 0);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2509 *pending++ = i915_request_get(*el->active);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2510 *pending++ = NULL;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2511
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2512 /* Tell the HW to preempt to our special context */
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2513 for (n = execlists_num_ports(el); --n; )
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2514 write_desc(el, 0, n);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2515 write_desc(el, desc, 0);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2516 if (el->ctrl_reg)
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2517 writel(EL_CTRL_LOAD, el->ctrl_reg);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2518
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2519 timeout = jiffies + HZ / 2;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2520 while (READ_ONCE(el->pending[0]) &&
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2521 time_before(jiffies, timeout))
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2522 intel_engine_flush_submission(engine);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2523
c3b2b6ffcd31318 Chris Wilson 2022-03-16 @2524 if (READ_ONCE(el->pending[0])) {
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2525 err = -EIO;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2526 goto err;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2527 }
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2528 }
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2529
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2530 goto out;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2531
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2532 err:
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2533 tasklet_disable(&se->tasklet);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2534 se->tasklet.callback = execlists_submission_tasklet;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2535 tasklet_enable(&se->tasklet);
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2536 out:
06139e9768f3f8e Tejas Upadhyay 2022-03-16 2537 intel_engine_pm_put(engine);
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2538 return err;
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2539 }
c3b2b6ffcd31318 Chris Wilson 2022-03-16 2540
---
0-DAY CI Kernel Test Service
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
More information about the Intel-gfx
mailing list