2022-07-08 17:26:00

by Ben Dooks

Subject: [PATCH 1/3] dmaengine: dw-axi-dmac: dump channel registers on error

On channel error, dump the channel register state before
the channel's LLI entries to see what the controller was
actually doing when the error happend.

Signed-off-by: Ben Dooks <[email protected]>
---
.../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 28 +++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index e9c9bcb1f5c2..75c537153e92 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -79,6 +79,20 @@ axi_chan_iowrite64(struct axi_dma_chan *chan, u32 reg, u64 val)
iowrite32(upper_32_bits(val), chan->chan_regs + reg + 4);
}

+static inline u64
+axi_chan_ioread64(struct axi_dma_chan *chan, u32 reg)
+{
+ u32 high, low;
+ u64 result;
+
+ low = ioread32(chan->chan_regs + reg);
+ high = ioread32(chan->chan_regs + reg + 4);
+
+ result = low;
+ result |= (u64)high << 32;
+ return result;
+}
+
static inline void axi_chan_config_write(struct axi_dma_chan *chan,
struct axi_dma_chan_config *config)
{
@@ -979,6 +993,18 @@ static int dw_axi_dma_chan_slave_config(struct dma_chan *dchan,
return 0;
}

+static void axi_chan_dump_regs(struct axi_dma_chan *chan)
+{
+ dev_err(dchan2dev(&chan->vc.chan),
+ "R: SAR: 0x%llx DAR: 0x%llx LLP: 0x%llx BTS 0x%x CTL: 0x%x:%08x\n",
+ axi_chan_ioread64(chan, CH_SAR),
+ axi_chan_ioread64(chan, CH_DAR),
+ axi_chan_ioread64(chan, CH_LLP),
+ axi_chan_ioread32(chan, CH_BLOCK_TS),
+ axi_chan_ioread32(chan, CH_CTL_H),
+ axi_chan_ioread32(chan, CH_CTL_L));
+}
+
static void axi_chan_dump_lli(struct axi_dma_chan *chan,
struct axi_dma_hw_desc *desc)
{
@@ -1020,6 +1046,8 @@ static noinline void axi_chan_handle_err(struct axi_dma_chan *chan, u32 status)
dev_err(chan2dev(chan),
"Bad descriptor submitted for %s, cookie: %d, irq: 0x%08x\n",
axi_chan_name(chan), vd->tx.cookie, status);
+
+ axi_chan_dump_regs(chan);
axi_chan_list_dump_lli(chan, vd_to_axi_desc(vd));

vchan_cookie_complete(vd);
--
2.35.1

2022-07-21 12:55:39

by Vinod Koul

Subject: Re: [PATCH 1/3] dmaengine: dw-axi-dmac: dump channel registers on error

On 08-07-22, 18:01, Ben Dooks wrote:
> On channel error, dump the channel register state before
> the channel's LLI entries to see what the controller was
> actually doing when the error happend.
>
> Signed-off-by: Ben Dooks <[email protected]>
> ---
> .../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> index e9c9bcb1f5c2..75c537153e92 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -79,6 +79,20 @@ axi_chan_iowrite64(struct axi_dma_chan *chan, u32 reg, u64 val)
> iowrite32(upper_32_bits(val), chan->chan_regs + reg + 4);
> }
>
> +static inline u64
> +axi_chan_ioread64(struct axi_dma_chan *chan, u32 reg)
> +{
> + u32 high, low;
> + u64 result;
> +
> + low = ioread32(chan->chan_regs + reg);
> + high = ioread32(chan->chan_regs + reg + 4);
> +
> + result = low;
> + result |= (u64)high << 32;
> + return result;
> +}

Better to use helpers like lo_hi_readq()?

> +
> static inline void axi_chan_config_write(struct axi_dma_chan *chan,
> struct axi_dma_chan_config *config)
> {
> @@ -979,6 +993,18 @@ static int dw_axi_dma_chan_slave_config(struct dma_chan *dchan,
> return 0;
> }
>
> +static void axi_chan_dump_regs(struct axi_dma_chan *chan)
> +{
> + dev_err(dchan2dev(&chan->vc.chan),
> + "R: SAR: 0x%llx DAR: 0x%llx LLP: 0x%llx BTS 0x%x CTL: 0x%x:%08x\n",
> + axi_chan_ioread64(chan, CH_SAR),
> + axi_chan_ioread64(chan, CH_DAR),
> + axi_chan_ioread64(chan, CH_LLP),
> + axi_chan_ioread32(chan, CH_BLOCK_TS),
> + axi_chan_ioread32(chan, CH_CTL_H),
> + axi_chan_ioread32(chan, CH_CTL_L));
> +}
> +
> static void axi_chan_dump_lli(struct axi_dma_chan *chan,
> struct axi_dma_hw_desc *desc)
> {
> @@ -1020,6 +1046,8 @@ static noinline void axi_chan_handle_err(struct axi_dma_chan *chan, u32 status)
> dev_err(chan2dev(chan),
> "Bad descriptor submitted for %s, cookie: %d, irq: 0x%08x\n",
> axi_chan_name(chan), vd->tx.cookie, status);
> +
> + axi_chan_dump_regs(chan);
> axi_chan_list_dump_lli(chan, vd_to_axi_desc(vd));
>
> vchan_cookie_complete(vd);
> --
> 2.35.1

--
~Vinod

2022-07-21 22:19:16

by Ben Dooks

Subject: Re: [PATCH 1/3] dmaengine: dw-axi-dmac: dump channel registers on error

On 21/07/2022 13:30, Vinod Koul wrote:
> On 08-07-22, 18:01, Ben Dooks wrote:
>> On channel error, dump the channel register state before
>> the channel's LLI entries to see what the controller was
>> actually doing when the error happend.
>>
>> Signed-off-by: Ben Dooks <[email protected]>
>> ---
>> .../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 28 +++++++++++++++++++
>> 1 file changed, 28 insertions(+)
>>
>> diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>> index e9c9bcb1f5c2..75c537153e92 100644
>> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>> @@ -79,6 +79,20 @@ axi_chan_iowrite64(struct axi_dma_chan *chan, u32 reg, u64 val)
>> iowrite32(upper_32_bits(val), chan->chan_regs + reg + 4);
>> }
>>
>> +static inline u64
>> +axi_chan_ioread64(struct axi_dma_chan *chan, u32 reg)
>> +{
>> + u32 high, low;
>> + u64 result;
>> +
>> + low = ioread32(chan->chan_regs + reg);
>> + high = ioread32(chan->chan_regs + reg + 4);
>> +
>> + result = low;
>> + result |= (u64)high << 32;
>> + return result;
>> +}
>
> Better to use helpers like lo_hi_readq()?

Will go check on those, thanks.