MLK-14609 ASoC: fsl_asrc: use snd_pcm_stream_lock_irqsave/restore

fsl_asrc_reset can be called from interrupt context with interrupts
disabled via sdma_int_handler -> imx_pcm_dma_complete. In this case we
need to make sure we don't reenable interrupts.

However, start_unlock_stream uses the _irq version of
snd_pcm_stream_unlock which means that interrupts will be enabled at
the end of that function.

This patch switches to the _irqsave/_irqrestore version of
snd_cpm_stream_lock/unlock to avoid the above issue and fix the
following warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:151 __handle_irq_event_percpu+0x150/0x154
irq 61 handler sdma_int_handler+0x0/0x34c enabled interrupts
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.11-02052-g4c94f9e-dirty #684
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[<8010ed08>] (unwind_backtrace) from [<8010b350>] (show_stack+0x10/0x14)
[<8010b350>] (show_stack) from [<803bae4c>] (dump_stack+0x88/0x9c)
[<803bae4c>] (dump_stack) from [<8012d82c>] (__warn+0xe8/0x100)
[<8012d82c>] (__warn) from [<8012d87c>] (warn_slowpath_fmt+0x38/0x48)
[<8012d87c>] (warn_slowpath_fmt) from [<80170a48>] (__handle_irq_event_percpu+0x150/0x154)
[<80170a48>] (__handle_irq_event_percpu) from [<80170a68>] (handle_irq_event_percpu+0x1c/0x58)
[<80170a68>] (handle_irq_event_percpu) from [<80170adc>] (handle_irq_event+0x38/0x5c)
[<80170adc>] (handle_irq_event) from [<80173e3c>] (handle_fasteoi_irq+0xd0/0x1a8)
[<80173e3c>] (handle_fasteoi_irq) from [<8016fc78>] (generic_handle_irq+0x24/0x34)
[<8016fc78>] (generic_handle_irq) from [<80170194>] (__handle_domain_irq+0x7c/0xec)
[<80170194>] (__handle_domain_irq) from [<801014c4>] (gic_handle_irq+0x48/0x8c)
[<801014c4>] (gic_handle_irq) from [<8010be8c>] (__irq_svc+0x6c/0xa8)
Exception stack(0x80f01f20 to 0x80f01f68)
1f20: 00000000 00000002 00000001 f4a00600 00000001 daf1ce68 4f334151 00000014
1f40: 4ef44986 00000014 00000004 80f03144 8010e30c 80f01f70 80999fb8 806c8808
1f60: 200f0013 ffffffff
[<8010be8c>] (__irq_svc) from [<806c8808>] (cpuidle_enter_state+0xec/0x264)
[<806c8808>] (cpuidle_enter_state) from [<80166e4c>] (cpu_startup_entry+0x148/0x21c)
[<80166e4c>] (cpu_startup_entry) from [<80e00c58>] (start_kernel+0x37c/0x388)
---[ end trace c7e4dec8204cf86b ]---

Signed-off-by: Octavian Purdila <octavian.purdila@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>

diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
index 9ee55c6..d83631d 100644 (file)
--- a/sound/soc/fsl/fsl_asrc.c
+++ b/sound/soc/fsl/fsl_asrc.c
@@ -849,22 +849,24 @@ static bool fsl_asrc_check_xrun(struct snd_pcm_substream *substream)
        return ret;
 }
 
-static int stop_lock_stream(struct snd_pcm_substream *substream)
+static int stop_lock_stream(struct snd_pcm_substream *substream,
+                           unsigned long *flags)
 {
        if (substream) {
-               snd_pcm_stream_lock_irq(substream);
+               snd_pcm_stream_lock_irqsave(substream, *flags);
                if (substream->runtime->status->state == SNDRV_PCM_STATE_RUNNING)
                        substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
        }
        return 0;
 }
 
-static int start_unlock_stream(struct snd_pcm_substream *substream)
+static int start_unlock_stream(struct snd_pcm_substream *substream,
+                              unsigned long *flags)
 {
        if (substream) {
                if (substream->runtime->status->state == SNDRV_PCM_STATE_RUNNING)
                        substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_START);
-               snd_pcm_stream_unlock_irq(substream);
+               snd_pcm_stream_unlock_irqrestore(substream, *flags);
        }
        return 0;
 }
@@ -877,10 +879,11 @@ static void fsl_asrc_reset(struct snd_pcm_substream *substream, bool stop)
        struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
        struct snd_soc_dpcm *dpcm;
        struct snd_pcm_substream *be_substream;
+       unsigned long flags0, flags1;
 
        if (stop) {
-               stop_lock_stream(asrc_priv->substream[0]);
-               stop_lock_stream(asrc_priv->substream[1]);
+               stop_lock_stream(asrc_priv->substream[0], &flags0);
+               stop_lock_stream(asrc_priv->substream[1], &flags1);
        }
 
        /* find the be for this fe stream */
@@ -898,8 +901,8 @@ static void fsl_asrc_reset(struct snd_pcm_substream *substream, bool stop)
        }
 
        if (stop) {
-               start_unlock_stream(asrc_priv->substream[1]);
-               start_unlock_stream(asrc_priv->substream[0]);
+               start_unlock_stream(asrc_priv->substream[1], &flags1);
+               start_unlock_stream(asrc_priv->substream[0], &flags0);
        }
 }