[PATCH AUTOSEL 6.3 33/37] ASoC: dwc: move DMA init to snd_soc_dai_driver probe()

From: Sasha Levin
Date: Wed May 31 2023 - 09:46:32 EST


From: Maxim Kochetkov <fido_max@xxxxxxxx>

[ Upstream commit 011a8719d6105dcb48077ea7a6a88ac019d4aa50 ]

When using DMA mode we are facing with Oops:
[ 396.458157] Unable to handle kernel access to user memory without uaccess routines at virtual address 000000000000000c
[ 396.469374] Oops [#1]
[ 396.471839] Modules linked in:
[ 396.475144] CPU: 0 PID: 114 Comm: arecord Not tainted 6.0.0-00164-g9a8eccdaf2be-dirty #68
[ 396.483619] Hardware name: YMP ELCT FPGA (DT)
[ 396.488156] epc : dmaengine_pcm_open+0x1d2/0x342
[ 396.493227] ra : dmaengine_pcm_open+0x1d2/0x342
[ 396.498140] epc : ffffffff807fe346 ra : ffffffff807fe346 sp : ffffffc804e138f0
[ 396.505602] gp : ffffffff817bf730 tp : ffffffd8042c8ac0 t0 : 6500000000000000
[ 396.513045] t1 : 0000000000000064 t2 : 656e69676e65616d s0 : ffffffc804e13990
[ 396.520477] s1 : ffffffd801b86a18 a0 : 0000000000000026 a1 : ffffffff816920f8
[ 396.527897] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 0000000000000000
[ 396.535319] a5 : 0000000000000000 a6 : ffffffd801b87040 a7 : 0000000000000038
[ 396.542740] s2 : ffffffd801b94a00 s3 : 0000000000000000 s4 : ffffffd80427f5e8
[ 396.550153] s5 : ffffffd80427f5e8 s6 : ffffffd801b44410 s7 : fffffffffffffff5
[ 396.557569] s8 : 0000000000000800 s9 : 0000000000000001 s10: ffffffff8066d254
[ 396.564978] s11: ffffffd8059cf768 t3 : ffffffff817d5577 t4 : ffffffff817d5577
[ 396.572391] t5 : ffffffff817d5578 t6 : ffffffc804e136e8
[ 396.577876] status: 0000000200000120 badaddr: 000000000000000c cause: 000000000000000d
[ 396.586007] [<ffffffff806839f4>] snd_soc_component_open+0x1a/0x68
[ 396.592439] [<ffffffff807fdd62>] __soc_pcm_open+0xf0/0x502
[ 396.598217] [<ffffffff80685d86>] soc_pcm_open+0x2e/0x4e
[ 396.603741] [<ffffffff8066cea4>] snd_pcm_open_substream+0x442/0x68e
[ 396.610313] [<ffffffff8066d1ea>] snd_pcm_open+0xfa/0x212
[ 396.615868] [<ffffffff8066d39c>] snd_pcm_capture_open+0x3a/0x60
[ 396.622048] [<ffffffff8065b35a>] snd_open+0xa8/0x17a
[ 396.627421] [<ffffffff801ae036>] chrdev_open+0xa0/0x218
[ 396.632893] [<ffffffff801a5a28>] do_dentry_open+0x17c/0x2a6
[ 396.638713] [<ffffffff801a6d9a>] vfs_open+0x1e/0x26
[ 396.643850] [<ffffffff801b8544>] path_openat+0x96e/0xc96
[ 396.649518] [<ffffffff801b9390>] do_filp_open+0x7c/0xf6
[ 396.655034] [<ffffffff801a6ff2>] do_sys_openat2+0x8a/0x11e
[ 396.660765] [<ffffffff801a735a>] sys_openat+0x50/0x7c
[ 396.666068] [<ffffffff80003aca>] ret_from_syscall+0x0/0x2
[ 396.674964] ---[ end trace 0000000000000000 ]---

It happens because of play_dma_data/capture_dma_data pointers are NULL.
Current implementation assigns these pointers at snd_soc_dai_driver
startup() callback and reset them back to NULL at shutdown(). But
soc_pcm_open() sequence uses DMA pointers in dmaengine_pcm_open()
before snd_soc_dai_driver startup().
Most generic DMA capable I2S drivers use snd_soc_dai_driver probe()
callback to init DMA pointers only once at probe. So move DMA init
to dw_i2s_dai_probe and drop shutdown() and startup() callbacks.

Signed-off-by: Maxim Kochetkov <fido_max@xxxxxxxx>
Link: https://lore.kernel.org/r/20230512110343.66664-1-fido_max@xxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/soc/dwc/dwc-i2s.c | 41 +++++++++--------------------------------
1 file changed, 9 insertions(+), 32 deletions(-)

diff --git a/sound/soc/dwc/dwc-i2s.c b/sound/soc/dwc/dwc-i2s.c
index 7f7dd07c63b2f..d2dd865e5ad89 100644
--- a/sound/soc/dwc/dwc-i2s.c
+++ b/sound/soc/dwc/dwc-i2s.c
@@ -183,30 +183,6 @@ static void i2s_stop(struct dw_i2s_dev *dev,
}
}

-static int dw_i2s_startup(struct snd_pcm_substream *substream,
- struct snd_soc_dai *cpu_dai)
-{
- struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
- union dw_i2s_snd_dma_data *dma_data = NULL;
-
- if (!(dev->capability & DWC_I2S_RECORD) &&
- (substream->stream == SNDRV_PCM_STREAM_CAPTURE))
- return -EINVAL;
-
- if (!(dev->capability & DWC_I2S_PLAY) &&
- (substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
- return -EINVAL;
-
- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
- dma_data = &dev->play_dma_data;
- else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
- dma_data = &dev->capture_dma_data;
-
- snd_soc_dai_set_dma_data(cpu_dai, substream, (void *)dma_data);
-
- return 0;
-}
-
static void dw_i2s_config(struct dw_i2s_dev *dev, int stream)
{
u32 ch_reg;
@@ -305,12 +281,6 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
return 0;
}

-static void dw_i2s_shutdown(struct snd_pcm_substream *substream,
- struct snd_soc_dai *dai)
-{
- snd_soc_dai_set_dma_data(dai, substream, NULL);
-}
-
static int dw_i2s_prepare(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
@@ -382,8 +352,6 @@ static int dw_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
}

static const struct snd_soc_dai_ops dw_i2s_dai_ops = {
- .startup = dw_i2s_startup,
- .shutdown = dw_i2s_shutdown,
.hw_params = dw_i2s_hw_params,
.prepare = dw_i2s_prepare,
.trigger = dw_i2s_trigger,
@@ -625,6 +593,14 @@ static int dw_configure_dai_by_dt(struct dw_i2s_dev *dev,

}

+static int dw_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+ struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ snd_soc_dai_init_dma_data(dai, &dev->play_dma_data, &dev->capture_dma_data);
+ return 0;
+}
+
static int dw_i2s_probe(struct platform_device *pdev)
{
const struct i2s_platform_data *pdata = pdev->dev.platform_data;
@@ -643,6 +619,7 @@ static int dw_i2s_probe(struct platform_device *pdev)
return -ENOMEM;

dw_i2s_dai->ops = &dw_i2s_dai_ops;
+ dw_i2s_dai->probe = dw_i2s_dai_probe;

dev->i2s_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(dev->i2s_base))
--
2.39.2