+#define PERIODS_MIN 2
+static unsigned int cdns_i2s_pcm_tx(struct cdns_i2s_dev *dev,
struct snd_pcm_runtime *runtime,unsigned int tx_ptr, bool *period_elapsed,snd_pcm_format_t format)+{
- unsigned int period_pos = tx_ptr % runtime->period_size;
not following what the modulo is for, usually it's modulo the buffer size?
This is to see if the new data is divisible by period_size and to determine whether it is enough for a period_size in the later loop.
That didn't answer to my question, the position is usually between 0..buffer_size.1.
Doing increments on a modulo value then comparisons as done below seems rather questionable.
iowrite32(data[0], dev->base + CDNS_FIFO_MEM);iowrite32(data[1], dev->base + CDNS_FIFO_MEM);period_pos++;if (++tx_ptr >= runtime->buffer_size)tx_ptr = 0;- }
- *period_elapsed = period_pos >= runtime->period_size;
- return tx_ptr;
+}
- pm_runtime_enable(&pdev->dev);
- if (pm_runtime_enabled(&pdev->dev))
cdns_i2s_runtime_suspend(&pdev->dev);that sequence looks suspicious.... Why would you suspend immediately during the probe? You're probably missing all the autosuspend stuff?
Since I have enabled clocks before, and the device is in the suspend state after pm_runtime_enable(), I need to disable clocks in cdns_i2s_runtime_suspend() to match the suspend state.
That is very odd on two counts a) if you haven't enabled the clocks, why do you need to disbale them? b) if you do a pm_runtime_enable(), then the branch if (pm_runtime_enabled) is always true.
- dev_dbg(&pdev->dev, "I2S supports %d stereo channels with %s.\n",
i2s->max_channels, ((i2s->irq < 0) ? "dma" : "interrupt"));- return 0;
+err:
- return ret;
+}
+static int cdns_i2s_remove(struct platform_device *pdev) {
- pm_runtime_disable(&pdev->dev);
- if (!pm_runtime_status_suspended(&pdev->dev))
cdns_i2s_runtime_suspend(&pdev->dev);... and this one too. Once you've disabled pm_runtime, checking the status is irrelevant...
I think the clocks need to be always enabled after probe if disable pm_runtime, and should be disabled when remove. This will do that.
if you are disabling pm_runtime, then the pm_runtime state becames invalid. When pm_runtime_disable() is added in remove operations, it's mainly to prevent the device from suspending.