Re: [alsa-devel] [PATCH 1/2] ASoC: rt5677: allow multiple interrupt sources

On Mon, Apr 01, 2019 at 02:55:18PM -0600, Fletcher Woodruff wrote:

From: Ben Zhang benzh@chromium.org

This patch allows headphone plug detect and mic present detect to be enabled at the same time. This patch implements an irq_chip with irq_domain directly instead of using regmap_irq, so that interrupt source line polarities can be flipped to support irq sharing.

regmap-irq should support active high/low, and if it doesn't it can't be a unique thing that only this device wants to implement so the common code should be improved.

• mutex_lock(&rt5677->irq_lock);
• /*

• * 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++) {

This looks unrelated to the polarity of the interupt?