diff options
| author | Lloyd Atkinson <latkinso@codeaurora.org> | 2017-09-18 16:51:24 -0400 |
|---|---|---|
| committer | Lakshmi Narayana Kalavala <lkalaval@codeaurora.org> | 2018-03-16 17:26:21 -0700 |
| commit | 3c6964a08c97236bf9a4938cf67becae4a0c5bf5 (patch) | |
| tree | 36aea76415b8f69f823da504b14a7cc3f2d6fb01 /drivers/gpu/drm | |
| parent | 1f9861ad386a36c435cf664c5a99e0e15de54c00 (diff) | |
drm/msm/sde: take irq callback lock before reading cb list
Take the callback spinlock before checking whether the callback
table list is empty. This resolves a race condition where the
callback list could be empty during the servicing of an
interrupt.
Change-Id: I8d59c0211526173ce98c8ca2dac36ec4743dc8f8
Signed-off-by: Lloyd Atkinson <latkinso@codeaurora.org>
Signed-off-by: Lakshmi Narayana Kalavala <lkalaval@codeaurora.org>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/msm/sde/sde_core_irq.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/gpu/drm/msm/sde/sde_core_irq.c b/drivers/gpu/drm/msm/sde/sde_core_irq.c index 83c8982b2e00..4f7e688650de 100644 --- a/drivers/gpu/drm/msm/sde/sde_core_irq.c +++ b/drivers/gpu/drm/msm/sde/sde_core_irq.c @@ -31,23 +31,35 @@ static void sde_core_irq_callback_handler(void *arg, int irq_idx) struct sde_irq *irq_obj = &sde_kms->irq_obj; struct sde_irq_callback *cb; unsigned long irq_flags; + bool cb_tbl_error = false; + int enable_counts = 0; pr_debug("irq_idx=%d\n", irq_idx); - if (list_empty(&irq_obj->irq_cb_tbl[irq_idx])) - SDE_ERROR("irq_idx=%d has no registered callback\n", irq_idx); + spin_lock_irqsave(&sde_kms->irq_obj.cb_lock, irq_flags); + if (list_empty(&irq_obj->irq_cb_tbl[irq_idx])) { + /* print error outside lock */ + cb_tbl_error = true; + enable_counts = atomic_read( + &sde_kms->irq_obj.enable_counts[irq_idx]); + } atomic_inc(&irq_obj->irq_counts[irq_idx]); /* * Perform registered function callback */ - spin_lock_irqsave(&sde_kms->irq_obj.cb_lock, irq_flags); list_for_each_entry(cb, &irq_obj->irq_cb_tbl[irq_idx], list) if (cb->func) cb->func(cb->arg, irq_idx); spin_unlock_irqrestore(&sde_kms->irq_obj.cb_lock, irq_flags); + if (cb_tbl_error) { + SDE_ERROR("irq has no registered callback, idx %d enables %d\n", + irq_idx, enable_counts); + SDE_EVT32_IRQ(irq_idx, enable_counts, SDE_EVTLOG_ERROR); + } + /* * Clear pending interrupt status in HW. * NOTE: sde_core_irq_callback_handler is protected by top-level |