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authorBen Zhang <benzh@chromium.org>2019-06-18 17:45:55 -0600
committerMark Brown <broonie@kernel.org>2019-06-19 12:46:44 +0100
commitdf9091e9d3f4500bc6fb15f5d2a1c2614f67004c (patch)
treea41e8bc8b26d6b913c51d193ce94af6ce6e07362
parent4f7b018b55db0361718161e1471d8b7a16fdfa47 (diff)
ASoC: rt5677: handle concurrent interrupts
The rt5677 driver writes to the IRQ control register within the IRQ handler in order to flip the polarity of the interrupts that have been signalled. If an interrupt fires in the interval between the regmap_read and the regmap_write, it will not trigger a new call to rt5677_irq. Add a bounded loop to rt5677_irq that keeps checking interrupts until none are seen, so that any interrupts that are signalled in that interval are correctly handled. Signed-off-by: Ben Zhang <benzh@chromium.org> Signed-off-by: Fletcher Woodruff <fletcherw@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--sound/soc/codecs/rt5677.c71
1 files changed, 45 insertions, 26 deletions
diff --git a/sound/soc/codecs/rt5677.c b/sound/soc/codecs/rt5677.c
index b5ae61ff87af..202af7135f07 100644
--- a/sound/soc/codecs/rt5677.c
+++ b/sound/soc/codecs/rt5677.c
@@ -5072,38 +5072,57 @@ static const struct rt5677_irq_desc rt5677_irq_descs[] = {
static irqreturn_t rt5677_irq(int unused, void *data)
{
struct rt5677_priv *rt5677 = data;
- int ret = 0, i, reg_irq, virq;
+ int ret = 0, loop, i, reg_irq, virq;
bool irq_fired = false;
mutex_lock(&rt5677->irq_lock);
- /* Read interrupt status */
- ret = regmap_read(rt5677->regmap, RT5677_IRQ_CTRL1, &reg_irq);
- if (ret) {
- dev_err(rt5677->dev, "failed reading IRQ status: %d\n", ret);
- goto exit;
- }
- for (i = 0; i < RT5677_IRQ_NUM; i++) {
- if (reg_irq & rt5677_irq_descs[i].status_mask) {
- irq_fired = true;
- virq = irq_find_mapping(rt5677->domain, i);
- if (virq)
- handle_nested_irq(virq);
-
- /* Clear the interrupt by flipping the polarity of the
- * interrupt source line that fired
- */
- reg_irq ^= rt5677_irq_descs[i].polarity_mask;
+ /*
+ * Loop to handle interrupts until the last i2c read shows no pending
+ * irqs. The interrupt line is shared by multiple interrupt sources.
+ * After the regmap_read() below, a new interrupt source line may
+ * become high before the regmap_write() finishes, so there isn't a
+ * rising edge on the shared interrupt line for the new interrupt. Thus,
+ * the loop is needed to avoid missing irqs.
+ *
+ * A safeguard of 20 loops is used to avoid hanging in the irq handler
+ * if there is something wrong with the interrupt status update. The
+ * interrupt sources here are audio jack plug/unplug events which
+ * shouldn't happen at a high frequency for a long period of time.
+ * Empirically, more than 3 loops have never been seen.
+ */
+ for (loop = 0; loop < 20; loop++) {
+ /* Read interrupt status */
+ ret = regmap_read(rt5677->regmap, RT5677_IRQ_CTRL1, &reg_irq);
+ if (ret) {
+ dev_err(rt5677->dev, "failed reading IRQ status: %d\n",
+ ret);
+ goto exit;
}
- }
- if (!irq_fired)
- goto exit;
-
- ret = regmap_write(rt5677->regmap, RT5677_IRQ_CTRL1, reg_irq);
- if (ret) {
- dev_err(rt5677->dev, "failed updating IRQ status: %d\n", ret);
- goto exit;
+ irq_fired = false;
+ for (i = 0; i < RT5677_IRQ_NUM; i++) {
+ if (reg_irq & rt5677_irq_descs[i].status_mask) {
+ irq_fired = true;
+ virq = irq_find_mapping(rt5677->domain, i);
+ if (virq)
+ handle_nested_irq(virq);
+
+ /* Clear the interrupt by flipping the polarity
+ * of the interrupt source line that fired
+ */
+ reg_irq ^= rt5677_irq_descs[i].polarity_mask;
+ }
+ }
+ if (!irq_fired)
+ goto exit;
+
+ ret = regmap_write(rt5677->regmap, RT5677_IRQ_CTRL1, reg_irq);
+ if (ret) {
+ dev_err(rt5677->dev, "failed updating IRQ status: %d\n",
+ ret);
+ goto exit;
+ }
}
exit:
mutex_unlock(&rt5677->irq_lock);