From: Stephen Boyd <swboyd@chromium.org>
To: Keerthy <j-keerthy@ti.com>, Tony Lindgren <tony@atomide.com>,
herbert@gondor.apana.org.au
Cc: Linux-OMAP <linux-omap@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Kristo, Tero" <t-kristo@ti.com>, Dave Gerlach <d-gerlach@ti.com>
Subject: Re: Suspend/Resume Broken on AM43/AM33 Platforms
Date: Sun, 18 Aug 2019 23:27:27 -0700 [thread overview]
Message-ID: <5d5a4150.1c69fb81.3faa2.eee8@mx.google.com> (raw)
In-Reply-To: <49fc7c64-88c0-74d0-2cb3-07986490941d@ti.com>
Quoting Keerthy (2019-08-18 21:24:58)
> Hi Stephen,
>
> commit 03a3bb7ae63150230c5de645dc95e673ebf17e1a
> Author: Stephen Boyd <swboyd@chromium.org>
> 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?
---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);
next prev parent reply other threads:[~2019-08-19 6:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 4:24 Suspend/Resume Broken on AM43/AM33 Platforms Keerthy
2019-08-19 6:27 ` Stephen Boyd [this message]
2019-08-19 7:27 ` Keerthy
2019-08-19 15:00 ` Stephen Boyd
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5d5a4150.1c69fb81.3faa2.eee8@mx.google.com \
--to=swboyd@chromium.org \
--cc=d-gerlach@ti.com \
--cc=herbert@gondor.apana.org.au \
--cc=j-keerthy@ti.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=t-kristo@ti.com \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).