On 19/08/19 11:57 AM, Stephen Boyd wrote:
Quoting Keerthy (2019-08-18 21:24:58)Hi Stephen, commit 03a3bb7ae63150230c5de645dc95e673ebf17e1a Author: Stephen Boyd <swboyd@xxxxxxxxxxxx> Date: Mon Aug 5 16:32:41 2019 -0700 hwrng: core - Freeze khwrng thread during suspend Commit seems to be breaking suspend/resume on TI AM43/AM33 platforms. rtcwake: wakeup from "mem" using /dev/rtc0 at Sun Nov 18 02:12:12 2018 [ 54.033833] PM: suspend entry (deep) [ 54.037741] Filesystems sync: 0.000 seconds [ 54.062730] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 54.071313] OOM killer disabled. [ 54.074572] Freezing remaining freezable tasks ... [ 74.083121] Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0): [ 74.092257] hwrng R running task 0 289 2 0x00000020 [ 74.099511] [<c08c64c4>] (__schedule) from [<c08c6a10>] (schedule+0x3c/0xc0) [ 74.106720] [<c08c6a10>] (schedule) from [<c05dbd8c>] (add_hwgenerator_randomness+0xb0/0x100) [ 74.115358] [<c05dbd8c>] (add_hwgenerator_randomness) from [<bf1803c8>] (hwrng_fillfn+0xc0/0x14c [rng_core])Thanks for the report. I suspect we need to check for freezer in add_hwgenerator_randomness(). I find it odd that there's another caller of add_hwgenerator_randomness(), but maybe the ath9k driver can be converted to some sort of hwrng driver instead of calling into the kthread directly. Anyway, can you try this patch?
I applied the below patch on top of latest next branch. Fixes the issue. Thanks, Keerthy
---8<--- diff --git a/drivers/char/random.c b/drivers/char/random.c index 5d5ea4ce1442..e2e85ca16410 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -2429,6 +2429,7 @@ void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy) { struct entropy_store *poolp = &input_pool; + bool frozen = false;if (unlikely(crng_init == 0)) {crng_fast_load(buffer, count); @@ -2439,9 +2440,12 @@ void add_hwgenerator_randomness(const char *buffer, size_t count, * We'll be woken up again once below random_write_wakeup_thresh, * or when the calling thread is about to terminate. */ - wait_event_interruptible(random_write_wait, kthread_should_stop() || + wait_event_interruptible(random_write_wait, + kthread_freezable_should_stop(&frozen) || ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits); - mix_pool_bytes(poolp, buffer, count); - credit_entropy_bits(poolp, entropy); + if (!frozen) { + mix_pool_bytes(poolp, buffer, count); + credit_entropy_bits(poolp, entropy); + } } EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
