* [PATCH] ASoC: AMD: Fix race condition between register access
@ 2018-10-29 7:38 Agrawal, Akshu
2018-10-30 1:32 ` Daniel Kurtz
0 siblings, 1 reply; 3+ messages in thread
From: Agrawal, Akshu @ 2018-10-29 7:38 UTC (permalink / raw)
Cc: Agrawal, Akshu, djkurtz, Deucher, Alexander, Liam Girdwood,
Mark Brown, Jaroslav Kysela, Takashi Iwai, Mukunda, Vijendar,
Deucher, Alexander, Guenter Roeck,
moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM...,
open list
During simultaneous running of playback and capture, we
got hit by incorrect value write on common register. This was due
to race condition between 2 streams.
Fixing this by locking the common register access.
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
---
sound/soc/amd/acp-pcm-dma.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index 0ac4b5b..993a7db 100644
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -121,6 +121,9 @@
.periods_max = CAPTURE_MAX_NUM_PERIODS,
};
+/* Lock to protect access to registers */
+static DEFINE_SPINLOCK(lock);
+
static u32 acp_reg_read(void __iomem *acp_mmio, u32 reg)
{
return readl(acp_mmio + (reg * 4));
@@ -168,9 +171,12 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
acp_dma_dscr_transfer_t *descr_info)
{
u32 sram_offset;
+ unsigned long flags;
sram_offset = (descr_idx * sizeof(acp_dma_dscr_transfer_t));
+ spin_lock_irqsave(&lock, flags);
+
/* program the source base address. */
acp_reg_write(sram_offset, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
acp_reg_write(descr_info->src, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
@@ -181,6 +187,8 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
/* program the number of bytes to be transferred for this descriptor. */
acp_reg_write(sram_offset + 8, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
acp_reg_write(descr_info->xfer_val, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
+
+ spin_unlock_irqrestore(&lock, flags);
}
static void pre_config_reset(void __iomem *acp_mmio, u16 ch_num)
@@ -309,8 +317,12 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
u32 low;
u32 high;
u32 offset;
+ unsigned long flags;
offset = ACP_DAGB_GRP_SRBM_SRAM_BASE_OFFSET + (pte_offset * 8);
+
+ spin_lock_irqsave(&lock, flags);
+
for (page_idx = 0; page_idx < (num_of_pages); page_idx++) {
/* Load the low address of page int ACP SRAM through SRBM */
acp_reg_write((offset + (page_idx * 8)),
@@ -333,6 +345,8 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
/* Move to next physically contiguos page */
pg++;
}
+
+ spin_unlock_irqrestore(&lock, flags);
}
static void config_acp_dma(void __iomem *acp_mmio,
@@ -367,6 +381,7 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
u16 cap_channel)
{
u32 val, ch_reg, imr_reg, res_reg;
+ unsigned long flags;
switch (cap_channel) {
case CAP_CHANNEL1:
@@ -381,6 +396,8 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
imr_reg = mmACP_I2SMICSP_IMR0;
break;
}
+ spin_lock_irqsave(&lock, flags);
+
val = acp_reg_read(acp_mmio,
mmACP_I2S_16BIT_RESOLUTION_EN);
if (val & ACP_I2S_MIC_16BIT_RESOLUTION_EN) {
@@ -393,12 +410,15 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
val &= ~ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
acp_reg_write(val, acp_mmio, imr_reg);
acp_reg_write(0x1, acp_mmio, ch_reg);
+
+ spin_unlock_irqrestore(&lock, flags);
}
static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
u16 cap_channel)
{
u32 val, ch_reg, imr_reg;
+ unsigned long flags;
switch (cap_channel) {
case CAP_CHANNEL1:
@@ -411,11 +431,15 @@ static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
ch_reg = mmACP_I2SMICSP_RER0;
break;
}
+ spin_lock_irqsave(&lock, flags);
+
val = acp_reg_read(acp_mmio, imr_reg);
val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXDAM_MASK;
val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
acp_reg_write(val, acp_mmio, imr_reg);
acp_reg_write(0x0, acp_mmio, ch_reg);
+
+ spin_unlock_irqrestore(&lock, flags);
}
/* Start a given DMA channel transfer */
@@ -847,6 +871,7 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
int status;
uint64_t size;
u32 val = 0;
+ unsigned long flags;
struct page *pg;
struct snd_pcm_runtime *runtime;
struct audio_substream_data *rtd;
@@ -870,6 +895,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
}
}
if (adata->asic_type == CHIP_STONEY) {
+ spin_lock_irqsave(&lock, flags);
+
val = acp_reg_read(adata->acp_mmio,
mmACP_I2S_16BIT_RESOLUTION_EN);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
@@ -893,6 +920,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
}
acp_reg_write(val, adata->acp_mmio,
mmACP_I2S_16BIT_RESOLUTION_EN);
+
+ spin_unlock_irqrestore(&lock, flags);
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ASoC: AMD: Fix race condition between register access
2018-10-29 7:38 [PATCH] ASoC: AMD: Fix race condition between register access Agrawal, Akshu
@ 2018-10-30 1:32 ` Daniel Kurtz
2018-10-30 15:48 ` Agrawal, Akshu
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Kurtz @ 2018-10-30 1:32 UTC (permalink / raw)
To: Akshu Agrawal
Cc: Alexander.Deucher, Liam Girdwood, Mark Brown, perex, tiwai,
Vijendar.Mukunda, Guenter Roeck, alsa-devel, linux-kernel
Hi Akshu,
On Mon, Oct 29, 2018 at 1:39 AM Agrawal, Akshu <Akshu.Agrawal@amd.com> wrote:
>
> During simultaneous running of playback and capture, we
> got hit by incorrect value write on common register. This was due
> to race condition between 2 streams.
> Fixing this by locking the common register access.
Nice catch! It looks looks like one of the operations you are trying
to make atomic is that two step Addr + Data register update.
If so, then I recommend refactoring a bit, and just doing that locked
2-step-access in its own helper function, like this:
static void acp_reg_write_srbm_targ(void __iomem *acp_mmio, u32
addr, u32 data)
{
unsigned long flags;
spin_lock_irqsave(&lock, flags);
acp_reg_write(addr, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
acp_reg_write(data, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
spin_unlock_irqrestore(&lock, flags);
}
And similarly, you can add 2 more locking helpers, one for modifying
the imr/ch and another for mmACP_I2S_16BIT_RESOLUTION_EN.
>
> Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
> ---
> sound/soc/amd/acp-pcm-dma.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
> index 0ac4b5b..993a7db 100644
> --- a/sound/soc/amd/acp-pcm-dma.c
> +++ b/sound/soc/amd/acp-pcm-dma.c
> @@ -121,6 +121,9 @@
> .periods_max = CAPTURE_MAX_NUM_PERIODS,
> };
>
> +/* Lock to protect access to registers */
> +static DEFINE_SPINLOCK(lock);
> +
> static u32 acp_reg_read(void __iomem *acp_mmio, u32 reg)
> {
> return readl(acp_mmio + (reg * 4));
> @@ -168,9 +171,12 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
> acp_dma_dscr_transfer_t *descr_info)
> {
> u32 sram_offset;
> + unsigned long flags;
>
> sram_offset = (descr_idx * sizeof(acp_dma_dscr_transfer_t));
>
> + spin_lock_irqsave(&lock, flags);
> +
> /* program the source base address. */
> acp_reg_write(sram_offset, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
> acp_reg_write(descr_info->src, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
> @@ -181,6 +187,8 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
> /* program the number of bytes to be transferred for this descriptor. */
> acp_reg_write(sram_offset + 8, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
> acp_reg_write(descr_info->xfer_val, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
> +
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> static void pre_config_reset(void __iomem *acp_mmio, u16 ch_num)
> @@ -309,8 +317,12 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
> u32 low;
> u32 high;
> u32 offset;
> + unsigned long flags;
>
> offset = ACP_DAGB_GRP_SRBM_SRAM_BASE_OFFSET + (pte_offset * 8);
> +
> + spin_lock_irqsave(&lock, flags);
> +
> for (page_idx = 0; page_idx < (num_of_pages); page_idx++) {
> /* Load the low address of page int ACP SRAM through SRBM */
> acp_reg_write((offset + (page_idx * 8)),
> @@ -333,6 +345,8 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
> /* Move to next physically contiguos page */
> pg++;
> }
> +
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> static void config_acp_dma(void __iomem *acp_mmio,
> @@ -367,6 +381,7 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
> u16 cap_channel)
> {
> u32 val, ch_reg, imr_reg, res_reg;
> + unsigned long flags;
>
> switch (cap_channel) {
> case CAP_CHANNEL1:
> @@ -381,6 +396,8 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
> imr_reg = mmACP_I2SMICSP_IMR0;
> break;
> }
> + spin_lock_irqsave(&lock, flags);
> +
> val = acp_reg_read(acp_mmio,
> mmACP_I2S_16BIT_RESOLUTION_EN);
> if (val & ACP_I2S_MIC_16BIT_RESOLUTION_EN) {
> @@ -393,12 +410,15 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
> val &= ~ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
> acp_reg_write(val, acp_mmio, imr_reg);
> acp_reg_write(0x1, acp_mmio, ch_reg);
> +
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
> u16 cap_channel)
> {
> u32 val, ch_reg, imr_reg;
> + unsigned long flags;
>
> switch (cap_channel) {
> case CAP_CHANNEL1:
> @@ -411,11 +431,15 @@ static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
> ch_reg = mmACP_I2SMICSP_RER0;
> break;
> }
> + spin_lock_irqsave(&lock, flags);
> +
> val = acp_reg_read(acp_mmio, imr_reg);
> val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXDAM_MASK;
> val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
> acp_reg_write(val, acp_mmio, imr_reg);
> acp_reg_write(0x0, acp_mmio, ch_reg);
> +
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> /* Start a given DMA channel transfer */
> @@ -847,6 +871,7 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
> int status;
> uint64_t size;
> u32 val = 0;
> + unsigned long flags;
> struct page *pg;
> struct snd_pcm_runtime *runtime;
> struct audio_substream_data *rtd;
> @@ -870,6 +895,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
> }
> }
> if (adata->asic_type == CHIP_STONEY) {
> + spin_lock_irqsave(&lock, flags);
> +
> val = acp_reg_read(adata->acp_mmio,
> mmACP_I2S_16BIT_RESOLUTION_EN);
> if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> @@ -893,6 +920,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
> }
> acp_reg_write(val, adata->acp_mmio,
> mmACP_I2S_16BIT_RESOLUTION_EN);
> +
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> --
> 1.9.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ASoC: AMD: Fix race condition between register access
2018-10-30 1:32 ` Daniel Kurtz
@ 2018-10-30 15:48 ` Agrawal, Akshu
0 siblings, 0 replies; 3+ messages in thread
From: Agrawal, Akshu @ 2018-10-30 15:48 UTC (permalink / raw)
To: Daniel Kurtz
Cc: Deucher, Alexander, Liam Girdwood, Mark Brown, perex, tiwai,
Mukunda, Vijendar, Guenter Roeck, alsa-devel, linux-kernel
On 10/30/2018 7:02 AM, Daniel Kurtz wrote:
> Hi Akshu,
>
>
> On Mon, Oct 29, 2018 at 1:39 AM Agrawal, Akshu <Akshu.Agrawal@amd.com> wrote:
>>
>> During simultaneous running of playback and capture, we
>> got hit by incorrect value write on common register. This was due
>> to race condition between 2 streams.
>> Fixing this by locking the common register access.
>
> Nice catch! It looks looks like one of the operations you are trying
> to make atomic is that two step Addr + Data register update.
> If so, then I recommend refactoring a bit, and just doing that locked
> 2-step-access in its own helper function, like this:
>
> static void acp_reg_write_srbm_targ(void __iomem *acp_mmio, u32
> addr, u32 data)
> {
> unsigned long flags;
>
> spin_lock_irqsave(&lock, flags);
> acp_reg_write(addr, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
> acp_reg_write(data, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
> spin_unlock_irqrestore(&lock, flags);
> }
>
> And similarly, you can add 2 more locking helpers, one for modifying
> the imr/ch and another for mmACP_I2S_16BIT_RESOLUTION_EN.
>
Accepted, will add the helper functions and push another patch.
Also, I noticed that locking is not needed in imr and ch reg as these
are separate registers for each channel, so will remove that.
Thanks,
Akshu
>>
>> Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
>> ---
>> sound/soc/amd/acp-pcm-dma.c | 29 +++++++++++++++++++++++++++++
>> 1 file changed, 29 insertions(+)
>>
>> diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
>> index 0ac4b5b..993a7db 100644
>> --- a/sound/soc/amd/acp-pcm-dma.c
>> +++ b/sound/soc/amd/acp-pcm-dma.c
>> @@ -121,6 +121,9 @@
>> .periods_max = CAPTURE_MAX_NUM_PERIODS,
>> };
>>
>> +/* Lock to protect access to registers */
>> +static DEFINE_SPINLOCK(lock);
>> +
>> static u32 acp_reg_read(void __iomem *acp_mmio, u32 reg)
>> {
>> return readl(acp_mmio + (reg * 4));
>> @@ -168,9 +171,12 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
>> acp_dma_dscr_transfer_t *descr_info)
>> {
>> u32 sram_offset;
>> + unsigned long flags;
>>
>> sram_offset = (descr_idx * sizeof(acp_dma_dscr_transfer_t));
>>
>> + spin_lock_irqsave(&lock, flags);
>> +
>> /* program the source base address. */
>> acp_reg_write(sram_offset, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
>> acp_reg_write(descr_info->src, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
>> @@ -181,6 +187,8 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
>> /* program the number of bytes to be transferred for this descriptor. */
>> acp_reg_write(sram_offset + 8, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
>> acp_reg_write(descr_info->xfer_val, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
>> +
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> static void pre_config_reset(void __iomem *acp_mmio, u16 ch_num)
>> @@ -309,8 +317,12 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
>> u32 low;
>> u32 high;
>> u32 offset;
>> + unsigned long flags;
>>
>> offset = ACP_DAGB_GRP_SRBM_SRAM_BASE_OFFSET + (pte_offset * 8);
>> +
>> + spin_lock_irqsave(&lock, flags);
>> +
>> for (page_idx = 0; page_idx < (num_of_pages); page_idx++) {
>> /* Load the low address of page int ACP SRAM through SRBM */
>> acp_reg_write((offset + (page_idx * 8)),
>> @@ -333,6 +345,8 @@ static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
>> /* Move to next physically contiguos page */
>> pg++;
>> }
>> +
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> static void config_acp_dma(void __iomem *acp_mmio,
>> @@ -367,6 +381,7 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
>> u16 cap_channel)
>> {
>> u32 val, ch_reg, imr_reg, res_reg;
>> + unsigned long flags;
>>
>> switch (cap_channel) {
>> case CAP_CHANNEL1:
>> @@ -381,6 +396,8 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
>> imr_reg = mmACP_I2SMICSP_IMR0;
>> break;
>> }
>> + spin_lock_irqsave(&lock, flags);
>> +
>> val = acp_reg_read(acp_mmio,
>> mmACP_I2S_16BIT_RESOLUTION_EN);
>> if (val & ACP_I2S_MIC_16BIT_RESOLUTION_EN) {
>> @@ -393,12 +410,15 @@ static void acp_dma_cap_channel_enable(void __iomem *acp_mmio,
>> val &= ~ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
>> acp_reg_write(val, acp_mmio, imr_reg);
>> acp_reg_write(0x1, acp_mmio, ch_reg);
>> +
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
>> u16 cap_channel)
>> {
>> u32 val, ch_reg, imr_reg;
>> + unsigned long flags;
>>
>> switch (cap_channel) {
>> case CAP_CHANNEL1:
>> @@ -411,11 +431,15 @@ static void acp_dma_cap_channel_disable(void __iomem *acp_mmio,
>> ch_reg = mmACP_I2SMICSP_RER0;
>> break;
>> }
>> + spin_lock_irqsave(&lock, flags);
>> +
>> val = acp_reg_read(acp_mmio, imr_reg);
>> val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXDAM_MASK;
>> val |= ACP_I2SMICSP_IMR1__I2SMICSP_RXFOM_MASK;
>> acp_reg_write(val, acp_mmio, imr_reg);
>> acp_reg_write(0x0, acp_mmio, ch_reg);
>> +
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> /* Start a given DMA channel transfer */
>> @@ -847,6 +871,7 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
>> int status;
>> uint64_t size;
>> u32 val = 0;
>> + unsigned long flags;
>> struct page *pg;
>> struct snd_pcm_runtime *runtime;
>> struct audio_substream_data *rtd;
>> @@ -870,6 +895,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
>> }
>> }
>> if (adata->asic_type == CHIP_STONEY) {
>> + spin_lock_irqsave(&lock, flags);
>> +
>> val = acp_reg_read(adata->acp_mmio,
>> mmACP_I2S_16BIT_RESOLUTION_EN);
>> if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
>> @@ -893,6 +920,8 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
>> }
>> acp_reg_write(val, adata->acp_mmio,
>> mmACP_I2S_16BIT_RESOLUTION_EN);
>> +
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
>> --
>> 1.9.1
>>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-10-30 15:49 UTC | newest]
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2018-10-30 15:48 ` Agrawal, Akshu
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