summaryrefslogtreecommitdiff
path: root/kernel/sched/core.c
diff options
context:
space:
mode:
authorMark Brown <broonie@kernel.org>2022-12-04 17:01:50 +0000
committerMark Brown <broonie@kernel.org>2022-12-04 17:01:50 +0000
commitf19a2caaab073873f673a41ce366ac898f34f543 (patch)
tree5e40ef8b2e30864406f01f0a09cbbeb153efcb42 /kernel/sched/core.c
parent969357ec94e670571d6593f2a93aba25e4577d4f (diff)
parenta04f1c81316d27e140c3df5561e5ef87794cd4bc (diff)
downloadlwn-f19a2caaab073873f673a41ce366ac898f34f543.tar.gz
lwn-f19a2caaab073873f673a41ce366ac898f34f543.zip
ASoC/tda998x: Fix reporting of nonexistent capture streams
Merge series from Mark Brown <broonie@kernel.org>: The recently added pcm-test selftest has pointed out that systems with the tda998x driver end up advertising that they support capture when in reality as far as I can see the tda998x devices are transmit only. The DAIs registered through hdmi-codec are bidirectional, meaning that for I2S systems when combined with a typical bidrectional CPU DAI the overall capability of the PCM is bidirectional. In most cases the I2S links will clock OK but no useful audio will be returned which isn't so bad but we should still not advertise the useless capability, and some systems may notice problems for example due to pinmux management. This is happening due to the hdmi-codec helpers not providing any mechanism for indicating unidirectional audio so add one and use it in the tda998x driver. It is likely other hdmi-codec users are also affected but I don't have those systems to hand. Mark Brown (2): ASoC: hdmi-codec: Allow playback and capture to be disabled drm: tda99x: Don't advertise non-existent capture support drivers/gpu/drm/i2c/tda998x_drv.c | 2 ++ include/sound/hdmi-codec.h | 4 ++++ sound/soc/codecs/hdmi-codec.c | 30 +++++++++++++++++++++++++----- 3 files changed, 31 insertions(+), 5 deletions(-) base-commit: f0c4d9fc9cc9462659728d168387191387e903cc -- 2.30.2
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r--kernel/sched/core.c52
1 files changed, 35 insertions, 17 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index cb2aa2b54c7a..daff72f00385 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4200,6 +4200,40 @@ out:
return success;
}
+static bool __task_needs_rq_lock(struct task_struct *p)
+{
+ unsigned int state = READ_ONCE(p->__state);
+
+ /*
+ * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when
+ * the task is blocked. Make sure to check @state since ttwu() can drop
+ * locks at the end, see ttwu_queue_wakelist().
+ */
+ if (state == TASK_RUNNING || state == TASK_WAKING)
+ return true;
+
+ /*
+ * Ensure we load p->on_rq after p->__state, otherwise it would be
+ * possible to, falsely, observe p->on_rq == 0.
+ *
+ * See try_to_wake_up() for a longer comment.
+ */
+ smp_rmb();
+ if (p->on_rq)
+ return true;
+
+#ifdef CONFIG_SMP
+ /*
+ * Ensure the task has finished __schedule() and will not be referenced
+ * anymore. Again, see try_to_wake_up() for a longer comment.
+ */
+ smp_rmb();
+ smp_cond_load_acquire(&p->on_cpu, !VAL);
+#endif
+
+ return false;
+}
+
/**
* task_call_func - Invoke a function on task in fixed state
* @p: Process for which the function is to be invoked, can be @current.
@@ -4217,28 +4251,12 @@ out:
int task_call_func(struct task_struct *p, task_call_f func, void *arg)
{
struct rq *rq = NULL;
- unsigned int state;
struct rq_flags rf;
int ret;
raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
- state = READ_ONCE(p->__state);
-
- /*
- * Ensure we load p->on_rq after p->__state, otherwise it would be
- * possible to, falsely, observe p->on_rq == 0.
- *
- * See try_to_wake_up() for a longer comment.
- */
- smp_rmb();
-
- /*
- * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when
- * the task is blocked. Make sure to check @state since ttwu() can drop
- * locks at the end, see ttwu_queue_wakelist().
- */
- if (state == TASK_RUNNING || state == TASK_WAKING || p->on_rq)
+ if (__task_needs_rq_lock(p))
rq = __task_rq_lock(p, &rf);
/*