Patchwork [5/5] dma: tegra: add tracepoints to driver

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Submitter Ben Dooks
Date Nov. 21, 2018, 4:13 p.m.
Message ID <20181121161323.20226-6-ben.dooks@codethink.co.uk>
Download mbox | patch
Permalink /patch/661927/
State New
Headers show

Comments

Ben Dooks - Nov. 21, 2018, 4:13 p.m.
Add some trace-points to the driver to allow for debuging via the
trace pipe.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
Fixes since v1:
- take copy of dmachan name instead of pointer to device

Fixes since v2:
- finish off Steven's review comments
- fix saving the dma channel name
- use txstate as argument to trace_tegra_dma_tx_status()
- fix type of dma_cookie to dma_cookie_t

Cc: Ingo Molnar <mingo@redhat.com> (maintainer:TRACING)
Cc: Steven Rostedt <rostedt@goodmis.org> (maintainer:TRACING)
---
 drivers/dma/tegra20-apb-dma.c        |  7 ++++
 include/trace/events/tegra_apb_dma.h | 61 ++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 include/trace/events/tegra_apb_dma.h
Steven Rostedt - Nov. 21, 2018, 5:21 p.m.
On Wed, 21 Nov 2018 16:13:23 +0000
Ben Dooks <ben.dooks@codethink.co.uk> wrote:

> Add some trace-points to the driver to allow for debuging via the
> trace pipe.
> 
> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>

From a tracing perspective I see nothing wrong with this patch.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

-- Steve


> ---
> Fixes since v1:
> - take copy of dmachan name instead of pointer to device
> 
> Fixes since v2:
> - finish off Steven's review comments
> - fix saving the dma channel name
> - use txstate as argument to trace_tegra_dma_tx_status()
> - fix type of dma_cookie to dma_cookie_t
> 
> Cc: Ingo Molnar <mingo@redhat.com> (maintainer:TRACING)
> Cc: Steven Rostedt <rostedt@goodmis.org> (maintainer:TRACING)
Ben Dooks - Nov. 22, 2018, 8:29 a.m.
On 21/11/2018 17:21, Steven Rostedt wrote:
> On Wed, 21 Nov 2018 16:13:23 +0000
> Ben Dooks <ben.dooks@codethink.co.uk> wrote:
> 
>> Add some trace-points to the driver to allow for debuging via the
>> trace pipe.
>>
>> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
> 
>  From a tracing perspective I see nothing wrong with this patch.
> 
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Thank you for the feedback.
Jon Hunter - Nov. 22, 2018, 8:55 a.m.
On 21/11/2018 16:13, Ben Dooks wrote:
> Add some trace-points to the driver to allow for debuging via the
> trace pipe.
> 
> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
> ---
> Fixes since v1:
> - take copy of dmachan name instead of pointer to device
> 
> Fixes since v2:
> - finish off Steven's review comments
> - fix saving the dma channel name
> - use txstate as argument to trace_tegra_dma_tx_status()
> - fix type of dma_cookie to dma_cookie_t
> 
> Cc: Ingo Molnar <mingo@redhat.com> (maintainer:TRACING)
> Cc: Steven Rostedt <rostedt@goodmis.org> (maintainer:TRACING)
> ---
>  drivers/dma/tegra20-apb-dma.c        |  7 ++++
>  include/trace/events/tegra_apb_dma.h | 61 ++++++++++++++++++++++++++++
>  2 files changed, 68 insertions(+)
>  create mode 100644 include/trace/events/tegra_apb_dma.h
> 
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index c60c3f7cad5f..659b49bf6fdb 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -38,6 +38,9 @@
>  
>  #include "dmaengine.h"
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/tegra_apb_dma.h>
> +
>  #define TEGRA_APBDMA_GENERAL			0x0
>  #define TEGRA_APBDMA_GENERAL_ENABLE		BIT(31)
>  
> @@ -672,6 +675,8 @@ static void tegra_dma_tasklet(unsigned long data)
>  		dmaengine_desc_get_callback(&dma_desc->txd, &cb);
>  		cb_count = dma_desc->cb_count;
>  		dma_desc->cb_count = 0;
> +		trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
> +					    cb.callback);
>  		spin_unlock_irqrestore(&tdc->lock, flags);
>  		while (cb_count--)
>  			dmaengine_desc_callback_invoke(&cb, NULL);
> @@ -688,6 +693,7 @@ static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
>  
>  	spin_lock_irqsave(&tdc->lock, flags);
>  
> +	trace_tegra_dma_isr(&tdc->dma_chan, irq);
>  	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
>  	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
>  		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
> @@ -846,6 +852,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
>  		dma_set_residue(txstate, residual);
>  	}
>  
> +	trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
>  	spin_unlock_irqrestore(&tdc->lock, flags);
>  	return ret;
>  }

My only comment here is that apart from the ISR trace, the others could
be added to the dmaengine driver core and then these could be used for
other DMAs as well.

Cheers
Jon
Ben Dooks - Nov. 22, 2018, 3:15 p.m.
On 22/11/2018 08:55, Jon Hunter wrote:
> 
> On 21/11/2018 16:13, Ben Dooks wrote:
>> Add some trace-points to the driver to allow for debuging via the
>> trace pipe.
>>
>> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
>> ---
>> Fixes since v1:
>> - take copy of dmachan name instead of pointer to device
>>
>> Fixes since v2:
>> - finish off Steven's review comments
>> - fix saving the dma channel name
>> - use txstate as argument to trace_tegra_dma_tx_status()
>> - fix type of dma_cookie to dma_cookie_t
>>
>> Cc: Ingo Molnar <mingo@redhat.com> (maintainer:TRACING)
>> Cc: Steven Rostedt <rostedt@goodmis.org> (maintainer:TRACING)
>> ---
>>   drivers/dma/tegra20-apb-dma.c        |  7 ++++
>>   include/trace/events/tegra_apb_dma.h | 61 ++++++++++++++++++++++++++++
>>   2 files changed, 68 insertions(+)
>>   create mode 100644 include/trace/events/tegra_apb_dma.h
>>
>> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
>> index c60c3f7cad5f..659b49bf6fdb 100644
>> --- a/drivers/dma/tegra20-apb-dma.c
>> +++ b/drivers/dma/tegra20-apb-dma.c
>> @@ -38,6 +38,9 @@
>>   
>>   #include "dmaengine.h"
>>   
>> +#define CREATE_TRACE_POINTS
>> +#include <trace/events/tegra_apb_dma.h>
>> +
>>   #define TEGRA_APBDMA_GENERAL			0x0
>>   #define TEGRA_APBDMA_GENERAL_ENABLE		BIT(31)
>>   
>> @@ -672,6 +675,8 @@ static void tegra_dma_tasklet(unsigned long data)
>>   		dmaengine_desc_get_callback(&dma_desc->txd, &cb);
>>   		cb_count = dma_desc->cb_count;
>>   		dma_desc->cb_count = 0;
>> +		trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
>> +					    cb.callback);
>>   		spin_unlock_irqrestore(&tdc->lock, flags);
>>   		while (cb_count--)
>>   			dmaengine_desc_callback_invoke(&cb, NULL);
>> @@ -688,6 +693,7 @@ static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
>>   
>>   	spin_lock_irqsave(&tdc->lock, flags);
>>   
>> +	trace_tegra_dma_isr(&tdc->dma_chan, irq);
>>   	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
>>   	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
>>   		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
>> @@ -846,6 +852,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
>>   		dma_set_residue(txstate, residual);
>>   	}
>>   
>> +	trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
>>   	spin_unlock_irqrestore(&tdc->lock, flags);
>>   	return ret;
>>   }
> 
> My only comment here is that apart from the ISR trace, the others could
> be added to the dmaengine driver core and then these could be used for
> other DMAs as well.

Hmm, I will go have a look at how difficult that would be.

Patch

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index c60c3f7cad5f..659b49bf6fdb 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -38,6 +38,9 @@ 
 
 #include "dmaengine.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/tegra_apb_dma.h>
+
 #define TEGRA_APBDMA_GENERAL			0x0
 #define TEGRA_APBDMA_GENERAL_ENABLE		BIT(31)
 
@@ -672,6 +675,8 @@  static void tegra_dma_tasklet(unsigned long data)
 		dmaengine_desc_get_callback(&dma_desc->txd, &cb);
 		cb_count = dma_desc->cb_count;
 		dma_desc->cb_count = 0;
+		trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
+					    cb.callback);
 		spin_unlock_irqrestore(&tdc->lock, flags);
 		while (cb_count--)
 			dmaengine_desc_callback_invoke(&cb, NULL);
@@ -688,6 +693,7 @@  static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 
 	spin_lock_irqsave(&tdc->lock, flags);
 
+	trace_tegra_dma_isr(&tdc->dma_chan, irq);
 	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
@@ -846,6 +852,7 @@  static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 		dma_set_residue(txstate, residual);
 	}
 
+	trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
 	spin_unlock_irqrestore(&tdc->lock, flags);
 	return ret;
 }
diff --git a/include/trace/events/tegra_apb_dma.h b/include/trace/events/tegra_apb_dma.h
new file mode 100644
index 000000000000..0818f6286110
--- /dev/null
+++ b/include/trace/events/tegra_apb_dma.h
@@ -0,0 +1,61 @@ 
+#if !defined(_TRACE_TEGRA_APB_DMA_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TEGRA_APM_DMA_H
+
+#include <linux/tracepoint.h>
+#include <linux/dmaengine.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM tegra_apb_dma
+
+TRACE_EVENT(tegra_dma_tx_status,
+	TP_PROTO(struct dma_chan *dc, dma_cookie_t cookie, struct dma_tx_state *state),
+	TP_ARGS(dc, cookie, state),
+	TP_STRUCT__entry(
+		__string(chan,	dev_name(&dc->dev->device))
+		__field(dma_cookie_t, cookie)
+		__field(__u32,	residue)
+	),
+	TP_fast_assign(
+		__assign_str(chan, dev_name(&dc->dev->device));
+		__entry->cookie = cookie;
+		__entry->residue = state ? state->residue : (u32)-1;
+	),
+	TP_printk("channel %s: dma cookie %d, residue %u",
+		  __get_str(chan), __entry->cookie, __entry->residue)
+);
+
+TRACE_EVENT(tegra_dma_complete_cb,
+	TP_PROTO(struct dma_chan *dc, int count, void *ptr),
+	TP_ARGS(dc, count, ptr),
+	TP_STRUCT__entry(
+		__string(chan,	dev_name(&dc->dev->device))
+		__field(int,	count)
+		__field(void *,	ptr)
+		),
+	TP_fast_assign(
+		__assign_str(chan, dev_name(&dc->dev->device));
+		__entry->count = count;
+		__entry->ptr = ptr;
+		),
+	TP_printk("channel %s: done %d, ptr %p",
+		  __get_str(chan), __entry->count, __entry->ptr)
+);
+
+TRACE_EVENT(tegra_dma_isr,
+	TP_PROTO(struct dma_chan *dc, int irq),
+	TP_ARGS(dc, irq),
+	TP_STRUCT__entry(
+		__string(chan,	dev_name(&dc->dev->device))
+		__field(int,	irq)
+	),
+	TP_fast_assign(
+		__assign_str(chan, dev_name(&dc->dev->device));
+		__entry->irq = irq;
+	),
+	TP_printk("%s: irq %d\n",  __get_str(chan), __entry->irq)
+);
+
+#endif /*  _TRACE_TEGRADMA_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>