53 lines
1.5 KiB
Diff
53 lines
1.5 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Pardha Saradhi K <pardha.saradhi.kesapragada@intel.com>
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Date: Tue, 18 Jul 2017 22:56:08 +0530
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Subject: [PATCH] ALSA: hda: Make sure DMA is stopped by reading back the RUN
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bit
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As per HW recommendation, after clearing the RUN bit,
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software must read a 0 from the RUN bit, before modifying
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related control registers or re-starting the DMA engine.
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Change-Id: Ied7c3534dde57fab7dc3eea809811933ced555b8
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Signed-off-by: Pardha Saradhi K <pardha.saradhi.kesapragada@intel.com>
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Reviewed-on:
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Reviewed-by: Prakash, Divya1
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Reviewed-by: Koul, Vinod <vinod.koul@intel.com>
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Tested-by: Sm, Bhadur A <bhadur.a.sm@intel.com>
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---
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sound/hda/hdac_stream.c | 16 ++++++++++++++++
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1 file changed, 16 insertions(+)
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diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c
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index 3c0c7c353566..2ddda76ba91d 100644
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--- a/sound/hda/hdac_stream.c
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+++ b/sound/hda/hdac_stream.c
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@@ -71,8 +71,24 @@ EXPORT_SYMBOL_GPL(snd_hdac_stream_start);
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*/
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void snd_hdac_stream_clear(struct hdac_stream *azx_dev)
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{
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+ int timeout;
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+ unsigned char val;
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+
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snd_hdac_stream_updateb(azx_dev, SD_CTL,
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SD_CTL_DMA_START | SD_INT_MASK, 0);
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+
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+ timeout = 300;
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+ do {
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+ udelay(3);
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+ val = snd_hdac_stream_readb(azx_dev, SD_CTL) &
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+ SD_CTL_DMA_START;
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+ if (!val)
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+ break;
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+ } while (--timeout);
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+
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+ if (!timeout)
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+ dev_err(azx_dev->bus->dev, "unable to stop the stream\n");
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+
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snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK); /* to be sure */
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azx_dev->running = false;
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}
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--
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https://clearlinux.org
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