[alsa-devel] [PATCH v2] ASoC: AMD: Fix race condition between register access
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 --- v2: Added 2 helper functions, removed locking in ch enable/disable as they are separate registers. sound/soc/amd/acp-pcm-dma.c | 63 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 48 insertions(+), 15 deletions(-)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index 0ac4b5b..5be9c2d 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)); @@ -131,6 +134,33 @@ static void acp_reg_write(u32 val, void __iomem *acp_mmio, u32 reg) writel(val, acp_mmio + (reg * 4)); }
+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); +} + +static void acp_reg_read_mod_write(void __iomem *acp_mmio, u32 addr, + u32 mask, bool set) +{ + u32 val; + unsigned long flags; + + spin_lock_irqsave(&lock, flags); + val = acp_reg_read(acp_mmio, addr); + if (set) + val |= mask; + else + val &= ~mask; + acp_reg_write(val, acp_mmio, addr); + spin_unlock_irqrestore(&lock, flags); +} + /* * Configure a given dma channel parameters - enable/disable, * number of descriptors, priority @@ -172,15 +202,12 @@ static void config_dma_descriptor_in_sram(void __iomem *acp_mmio, sram_offset = (descr_idx * sizeof(acp_dma_dscr_transfer_t));
/* 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); + acp_reg_write_srbm_targ(acp_mmio, sram_offset, descr_info->src); /* program the destination base address. */ - acp_reg_write(sram_offset + 4, acp_mmio, mmACP_SRBM_Targ_Idx_Addr); - acp_reg_write(descr_info->dest, acp_mmio, mmACP_SRBM_Targ_Idx_Data); - + acp_reg_write_srbm_targ(acp_mmio, sram_offset + 4, descr_info->dest); /* 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); + acp_reg_write_srbm_targ(acp_mmio, sram_offset + 8, + descr_info->xfer_val); }
static void pre_config_reset(void __iomem *acp_mmio, u16 ch_num) @@ -309,8 +336,12 @@ 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 +364,8 @@ 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, @@ -870,29 +903,29 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream, } } if (adata->asic_type == CHIP_STONEY) { - val = acp_reg_read(adata->acp_mmio, - mmACP_I2S_16BIT_RESOLUTION_EN); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { switch (rtd->i2s_instance) { case I2S_BT_INSTANCE: - val |= ACP_I2S_BT_16BIT_RESOLUTION_EN; + val = ACP_I2S_BT_16BIT_RESOLUTION_EN; break; case I2S_SP_INSTANCE: default: - val |= ACP_I2S_SP_16BIT_RESOLUTION_EN; + val = ACP_I2S_SP_16BIT_RESOLUTION_EN; } } else { switch (rtd->i2s_instance) { case I2S_BT_INSTANCE: - val |= ACP_I2S_BT_16BIT_RESOLUTION_EN; + val = ACP_I2S_BT_16BIT_RESOLUTION_EN; break; case I2S_SP_INSTANCE: default: - val |= ACP_I2S_MIC_16BIT_RESOLUTION_EN; + val = ACP_I2S_MIC_16BIT_RESOLUTION_EN; } } - acp_reg_write(val, adata->acp_mmio, - mmACP_I2S_16BIT_RESOLUTION_EN); + acp_reg_read_mod_write(adata->acp_mmio, + mmACP_I2S_16BIT_RESOLUTION_EN, + val, + true); }
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
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Agrawal, Akshu