ALSA: hda: Add dma stop delay variable (4106820b) · Commits · 戴 / test

A variable dma_stop_delay is added as a new member in hdac_bus structure to avoid memory decode error incase DMA RUN bit is not disabled in the given timeout from snd_hdac_stream_sync function and followed by stream reset which results in memory decode error between reset set and clear operation. Signed-off-by:

Mohan Kumar <mkumard@nvidia.com> Link: https://lore.kernel.org/r/20200805095221.5476-3-mkumard@nvidia.com Signed-off-by:

Takashi Iwai <tiwai@suse.de>

include/sound/hdaudio.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -347,6 +347,9 @@ struct hdac_bus {

		int bdl_pos_adj; /* BDL position adjustment */

		/* delay time in us for dma stop */
		unsigned int dma_stop_delay;

		/* locks */
		spinlock_t reg_lock;
		struct mutex cmd_mutex;

sound/hda/hdac_stream.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -150,9 +150,12 @@ void snd_hdac_stream_reset(struct hdac_stream *azx_dev)
		{
		unsigned char val;
		int timeout;
		int dma_run_state;

		snd_hdac_stream_clear(azx_dev);

		dma_run_state = snd_hdac_stream_readb(azx_dev, SD_CTL) & SD_CTL_DMA_START;

		snd_hdac_stream_updateb(azx_dev, SD_CTL, 0, SD_CTL_STREAM_RESET);
		udelay(3);
		timeout = 300;
		@@ -162,6 +165,10 @@ void snd_hdac_stream_reset(struct hdac_stream *azx_dev)
		if (val)
		break;
		} while (--timeout);

		if (azx_dev->bus->dma_stop_delay && dma_run_state)
		udelay(azx_dev->bus->dma_stop_delay);

		val &= ~SD_CTL_STREAM_RESET;
		snd_hdac_stream_writeb(azx_dev, SD_CTL, val);
		udelay(3);

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