Via the /sys/kernel/debug/dmaengine users can get information about the
DMA devices and the used channels.
Example output on am654-evm with audio using two channels and after running
dmatest on 6 channels:
# cat /sys/kernel/debug/dmaengine
dma0 (285c0000.dma-controller): number of channels: 96
dma1 (31150000.dma-controller): number of channels: 267
dma1chan0 | 2b00000.mcasp:tx
dma1chan1 | 2b00000.mcasp:rx
dma1chan2 | in-use
dma1chan3 | in-use
dma1chan4 | in-use
dma1chan5 | in-use
dma1chan6 | in-use
dma1chan7 | in-use
For slave channels we can show the device and the channel name a given
channel is requested.
For non slave devices the only information we know is that the channel is
in use.
DMA drivers can implement the optional dbg_show callback to provide
controller specific information instead of the generic one.
It is easy to extend the generic dmaengine_dbg_show() to print additional
information about the used channels.
I have taken the idea from gpiolib.
Signed-off-by: Peter Ujfalusi <[email protected]>
---
Hi,
Changes since v2:
- Use dma_chan_name() for printing the channel's name
Changes since v1:
- Use much more simplified fops for the debugfs file (via DEFINE_SHOW_ATTRIBUTE)
- do not allow modification to dma_device_list while the debugfs file is read
- rename the slave_name to dbg_client_name (it is only for debugging)
- print information about dma_router if it is used by the channel
- Formating of the output slightly changed
Regards,
Peter
drivers/dma/dmaengine.c | 65 +++++++++++++++++++++++++++++++++++++++
include/linux/dmaengine.h | 12 +++++++-
2 files changed, 76 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index c3b1283b6d31..37c3a4cd5b1a 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -32,6 +32,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/platform_device.h>
+#include <linux/debugfs.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/module.h>
@@ -760,6 +761,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
found:
+#ifdef CONFIG_DEBUG_FS
+ chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
+ name);
+#endif
+
chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
if (!chan->name)
return chan;
@@ -837,6 +843,11 @@ void dma_release_channel(struct dma_chan *chan)
chan->name = NULL;
chan->slave = NULL;
}
+
+#ifdef CONFIG_DEBUG_FS
+ kfree(chan->dbg_client_name);
+ chan->dbg_client_name = NULL;
+#endif
mutex_unlock(&dma_list_mutex);
}
EXPORT_SYMBOL_GPL(dma_release_channel);
@@ -1562,3 +1573,57 @@ static int __init dma_bus_init(void)
return class_register(&dma_devclass);
}
arch_initcall(dma_bus_init);
+
+#ifdef CONFIG_DEBUG_FS
+static void dmaengine_dbg_show(struct seq_file *s, struct dma_device *dma_dev)
+{
+ struct dma_chan *chan;
+
+ list_for_each_entry(chan, &dma_dev->channels, device_node) {
+ if (chan->client_count) {
+ seq_printf(s, " %-13s| %s", dma_chan_name(chan),
+ chan->dbg_client_name ?: "in-use");
+
+ if (chan->router)
+ seq_printf(s, " (via router: %s)\n",
+ dev_name(chan->router->dev));
+ else
+ seq_puts(s, "\n");
+ }
+ }
+}
+
+static int dmaengine_debugfs_show(struct seq_file *s, void *data)
+{
+ struct dma_device *dma_dev = NULL;
+
+ mutex_lock(&dma_list_mutex);
+ list_for_each_entry(dma_dev, &dma_device_list, global_node) {
+ seq_printf(s, "dma%d (%s): number of channels: %u\n",
+ dma_dev->dev_id, dev_name(dma_dev->dev),
+ dma_dev->chancnt);
+
+ if (dma_dev->dbg_show)
+ dma_dev->dbg_show(s, dma_dev);
+ else
+ dmaengine_dbg_show(s, dma_dev);
+
+ if (!list_is_last(&dma_dev->global_node, &dma_device_list))
+ seq_puts(s, "\n");
+ }
+ mutex_unlock(&dma_list_mutex);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
+
+static int __init dmaengine_debugfs_init(void)
+{
+ /* /sys/kernel/debug/dmaengine */
+ debugfs_create_file("dmaengine", 0444, NULL, NULL,
+ &dmaengine_debugfs_fops);
+ return 0;
+}
+late_initcall(dmaengine_debugfs_init);
+
+#endif /* DEBUG_FS */
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 64461fc64e1b..9f232b7618f1 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -300,6 +300,8 @@ struct dma_router {
* @chan_id: channel ID for sysfs
* @dev: class device for sysfs
* @name: backlink name for sysfs
+ * @dbg_client_name: slave name for debugfs in format:
+ * dev_name(requester's dev):channel name, for example: "2b00000.mcasp:tx"
* @device_node: used to add this to the device chan list
* @local: per-cpu pointer to a struct dma_chan_percpu
* @client_count: how many clients are using this channel
@@ -318,6 +320,9 @@ struct dma_chan {
int chan_id;
struct dma_chan_dev *dev;
const char *name;
+#ifdef CONFIG_DEBUG_FS
+ char *dbg_client_name;
+#endif
struct list_head device_node;
struct dma_chan_percpu __percpu *local;
@@ -805,7 +810,9 @@ struct dma_filter {
* called and there are no further references to this structure. This
* must be implemented to free resources however many existing drivers
* do not and are therefore not safe to unbind while in use.
- *
+ * @dbg_show: optional routine to show contents in debugfs; default code
+ * will be used when this is omitted, but custom code can show extra,
+ * controller specific information.
*/
struct dma_device {
struct kref ref;
@@ -891,6 +898,9 @@ struct dma_device {
struct dma_tx_state *txstate);
void (*device_issue_pending)(struct dma_chan *chan);
void (*device_release)(struct dma_device *dev);
+#ifdef CONFIG_DEBUG_FS
+ void (*dbg_show)(struct seq_file *s, struct dma_device *dev);
+#endif
};
static inline int dmaengine_slave_config(struct dma_chan *chan,
--
Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On 05-02-20, 13:15, Peter Ujfalusi wrote:
> Via the /sys/kernel/debug/dmaengine users can get information about the
> DMA devices and the used channels.
>
> Example output on am654-evm with audio using two channels and after running
> dmatest on 6 channels:
>
> # cat /sys/kernel/debug/dmaengine
> dma0 (285c0000.dma-controller): number of channels: 96
>
> dma1 (31150000.dma-controller): number of channels: 267
> dma1chan0 | 2b00000.mcasp:tx
> dma1chan1 | 2b00000.mcasp:rx
> dma1chan2 | in-use
> dma1chan3 | in-use
> dma1chan4 | in-use
> dma1chan5 | in-use
> dma1chan6 | in-use
> dma1chan7 | in-use
>
> For slave channels we can show the device and the channel name a given
> channel is requested.
> For non slave devices the only information we know is that the channel is
> in use.
>
> DMA drivers can implement the optional dbg_show callback to provide
> controller specific information instead of the generic one.
>
> It is easy to extend the generic dmaengine_dbg_show() to print additional
> information about the used channels.
>
> I have taken the idea from gpiolib.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> Hi,
>
> Changes since v2:
> - Use dma_chan_name() for printing the channel's name
>
> Changes since v1:
> - Use much more simplified fops for the debugfs file (via DEFINE_SHOW_ATTRIBUTE)
> - do not allow modification to dma_device_list while the debugfs file is read
> - rename the slave_name to dbg_client_name (it is only for debugging)
> - print information about dma_router if it is used by the channel
> - Formating of the output slightly changed
>
> Regards,
> Peter
>
> drivers/dma/dmaengine.c | 65 +++++++++++++++++++++++++++++++++++++++
> include/linux/dmaengine.h | 12 +++++++-
> 2 files changed, 76 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index c3b1283b6d31..37c3a4cd5b1a 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -32,6 +32,7 @@
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> #include <linux/platform_device.h>
> +#include <linux/debugfs.h>
> #include <linux/dma-mapping.h>
> #include <linux/init.h>
> #include <linux/module.h>
> @@ -760,6 +761,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
> return chan ? chan : ERR_PTR(-EPROBE_DEFER);
>
> found:
> +#ifdef CONFIG_DEBUG_FS
> + chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
> + name);
> +#endif
> +
> chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
> if (!chan->name)
> return chan;
> @@ -837,6 +843,11 @@ void dma_release_channel(struct dma_chan *chan)
> chan->name = NULL;
> chan->slave = NULL;
> }
> +
> +#ifdef CONFIG_DEBUG_FS
> + kfree(chan->dbg_client_name);
> + chan->dbg_client_name = NULL;
> +#endif
> mutex_unlock(&dma_list_mutex);
> }
> EXPORT_SYMBOL_GPL(dma_release_channel);
> @@ -1562,3 +1573,57 @@ static int __init dma_bus_init(void)
> return class_register(&dma_devclass);
> }
> arch_initcall(dma_bus_init);
> +
> +#ifdef CONFIG_DEBUG_FS
> +static void dmaengine_dbg_show(struct seq_file *s, struct dma_device *dma_dev)
> +{
> + struct dma_chan *chan;
> +
> + list_for_each_entry(chan, &dma_dev->channels, device_node) {
> + if (chan->client_count) {
> + seq_printf(s, " %-13s| %s", dma_chan_name(chan),
> + chan->dbg_client_name ?: "in-use");
> +
> + if (chan->router)
> + seq_printf(s, " (via router: %s)\n",
> + dev_name(chan->router->dev));
> + else
> + seq_puts(s, "\n");
> + }
> + }
> +}
> +
> +static int dmaengine_debugfs_show(struct seq_file *s, void *data)
> +{
> + struct dma_device *dma_dev = NULL;
> +
> + mutex_lock(&dma_list_mutex);
> + list_for_each_entry(dma_dev, &dma_device_list, global_node) {
> + seq_printf(s, "dma%d (%s): number of channels: %u\n",
> + dma_dev->dev_id, dev_name(dma_dev->dev),
> + dma_dev->chancnt);
> +
> + if (dma_dev->dbg_show)
> + dma_dev->dbg_show(s, dma_dev);
do we really want a custom dbg_show()..? Drivers can add their own
files...
> + else
> + dmaengine_dbg_show(s, dma_dev);
> +
> + if (!list_is_last(&dma_dev->global_node, &dma_device_list))
> + seq_puts(s, "\n");
> + }
> + mutex_unlock(&dma_list_mutex);
> +
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
> +
> +static int __init dmaengine_debugfs_init(void)
> +{
> + /* /sys/kernel/debug/dmaengine */
> + debugfs_create_file("dmaengine", 0444, NULL, NULL,
> + &dmaengine_debugfs_fops);
Should we add a directory? That way we can keep adding stuff into that
one
--
~Vinod
Hi Vinod,
On 2/24/20 6:37 PM, Vinod Koul wrote:
> On 05-02-20, 13:15, Peter Ujfalusi wrote:
>> Via the /sys/kernel/debug/dmaengine users can get information about the
>> DMA devices and the used channels.
>>
>> Example output on am654-evm with audio using two channels and after running
>> dmatest on 6 channels:
>>
>> # cat /sys/kernel/debug/dmaengine
>> dma0 (285c0000.dma-controller): number of channels: 96
>>
>> dma1 (31150000.dma-controller): number of channels: 267
>> dma1chan0 | 2b00000.mcasp:tx
>> dma1chan1 | 2b00000.mcasp:rx
>> dma1chan2 | in-use
>> dma1chan3 | in-use
>> dma1chan4 | in-use
>> dma1chan5 | in-use
>> dma1chan6 | in-use
>> dma1chan7 | in-use
>>
>> For slave channels we can show the device and the channel name a given
>> channel is requested.
>> For non slave devices the only information we know is that the channel is
>> in use.
>>
>> DMA drivers can implement the optional dbg_show callback to provide
>> controller specific information instead of the generic one.
>>
>> It is easy to extend the generic dmaengine_dbg_show() to print additional
>> information about the used channels.
>>
>> I have taken the idea from gpiolib.
>>
>> Signed-off-by: Peter Ujfalusi <[email protected]>
>> ---
>> Hi,
>>
>> Changes since v2:
>> - Use dma_chan_name() for printing the channel's name
>>
>> Changes since v1:
>> - Use much more simplified fops for the debugfs file (via DEFINE_SHOW_ATTRIBUTE)
>> - do not allow modification to dma_device_list while the debugfs file is read
>> - rename the slave_name to dbg_client_name (it is only for debugging)
>> - print information about dma_router if it is used by the channel
>> - Formating of the output slightly changed
>>
>> Regards,
>> Peter
>>
>> drivers/dma/dmaengine.c | 65 +++++++++++++++++++++++++++++++++++++++
>> include/linux/dmaengine.h | 12 +++++++-
>> 2 files changed, 76 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
>> index c3b1283b6d31..37c3a4cd5b1a 100644
>> --- a/drivers/dma/dmaengine.c
>> +++ b/drivers/dma/dmaengine.c
>> @@ -32,6 +32,7 @@
>> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>>
>> #include <linux/platform_device.h>
>> +#include <linux/debugfs.h>
>> #include <linux/dma-mapping.h>
>> #include <linux/init.h>
>> #include <linux/module.h>
>> @@ -760,6 +761,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
>> return chan ? chan : ERR_PTR(-EPROBE_DEFER);
>>
>> found:
>> +#ifdef CONFIG_DEBUG_FS
>> + chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
>> + name);
>> +#endif
>> +
>> chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
>> if (!chan->name)
>> return chan;
>> @@ -837,6 +843,11 @@ void dma_release_channel(struct dma_chan *chan)
>> chan->name = NULL;
>> chan->slave = NULL;
>> }
>> +
>> +#ifdef CONFIG_DEBUG_FS
>> + kfree(chan->dbg_client_name);
>> + chan->dbg_client_name = NULL;
>> +#endif
>> mutex_unlock(&dma_list_mutex);
>> }
>> EXPORT_SYMBOL_GPL(dma_release_channel);
>> @@ -1562,3 +1573,57 @@ static int __init dma_bus_init(void)
>> return class_register(&dma_devclass);
>> }
>> arch_initcall(dma_bus_init);
>> +
>> +#ifdef CONFIG_DEBUG_FS
>> +static void dmaengine_dbg_show(struct seq_file *s, struct dma_device *dma_dev)
>> +{
>> + struct dma_chan *chan;
>> +
>> + list_for_each_entry(chan, &dma_dev->channels, device_node) {
>> + if (chan->client_count) {
>> + seq_printf(s, " %-13s| %s", dma_chan_name(chan),
>> + chan->dbg_client_name ?: "in-use");
>> +
>> + if (chan->router)
>> + seq_printf(s, " (via router: %s)\n",
>> + dev_name(chan->router->dev));
>> + else
>> + seq_puts(s, "\n");
>> + }
>> + }
>> +}
>> +
>> +static int dmaengine_debugfs_show(struct seq_file *s, void *data)
>> +{
>> + struct dma_device *dma_dev = NULL;
>> +
>> + mutex_lock(&dma_list_mutex);
>> + list_for_each_entry(dma_dev, &dma_device_list, global_node) {
>> + seq_printf(s, "dma%d (%s): number of channels: %u\n",
>> + dma_dev->dev_id, dev_name(dma_dev->dev),
>> + dma_dev->chancnt);
>> +
>> + if (dma_dev->dbg_show)
>> + dma_dev->dbg_show(s, dma_dev);
> do we really want a custom dbg_show()..? Drivers can add their own
> files...
They could do that already ;)
With the custom dbg_show() DMA drivers can save on the surrounding
code and just fill in the information regarding to their HW.
Again, on am654 the default information is:
# cat /sys/kernel/debug/dmaengine
dma0 (285c0000.dma-controller): number of channels: 96
dma1 (31150000.dma-controller): number of channels: 267
dma1chan0 | 2b00000.mcasp:tx
dma1chan1 | 2b00000.mcasp:rx
dma1chan2 | in-use
dma1chan3 | in-use
dma1chan4 | in-use
dma1chan5 | in-use
With my current .dbg_show implementation for k3-udma:
# cat /sys/kernel/debug/dmaengine
dma0 (285c0000.dma-controller): number of channels: 96
dma1 (31150000.dma-controller): number of channels: 267
dma1chan0 | 2b00000.mcasp:tx (MEM_TO_DEV, tchan8 [0x1008 -> 0xc400], PDMA, TR mode)
dma1chan1 | 2b00000.mcasp:rx (DEV_TO_MEM, rchan8 [0x4400 -> 0x9008], PDMA, TR mode)
dma1chan2 | in-use (MEM_TO_MEM, chan2 pair [0x1002 -> 0x9002], PSI-L Native, TR mode)
dma1chan3 | in-use (MEM_TO_MEM, chan3 pair [0x1003 -> 0x9003], PSI-L Native, TR mode)
dma1chan4 | in-use (MEM_TO_MEM, chan4 pair [0x1004 -> 0x9004], PSI-L Native, TR mode)
dma1chan5 | in-use (MEM_TO_MEM, chan5 pair [0x1005 -> 0x9005], PSI-L Native, TR mode)
For me this makes a huge difference.
>
>> + else
>> + dmaengine_dbg_show(s, dma_dev);
>> +
>> + if (!list_is_last(&dma_dev->global_node, &dma_device_list))
>> + seq_puts(s, "\n");
>> + }
>> + mutex_unlock(&dma_list_mutex);
>> +
>> + return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
>> +
>> +static int __init dmaengine_debugfs_init(void)
>> +{
>> + /* /sys/kernel/debug/dmaengine */
>> + debugfs_create_file("dmaengine", 0444, NULL, NULL,
>> + &dmaengine_debugfs_fops);
>
> Should we add a directory? That way we can keep adding stuff into that
> one
and have this file as 'summary' underneath?
I like the fact hat I can get all the information via one file.
Saves a lot of time (and explaining to users) on finding the correct
one to cat...
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
Hi Peter,
On 26-02-20, 14:10, Peter Ujfalusi wrote:
> > do we really want a custom dbg_show()..? Drivers can add their own
> > files...
>
> They could do that already ;)
>
> With the custom dbg_show() DMA drivers can save on the surrounding
> code and just fill in the information regarding to their HW.
> Again, on am654 the default information is:
> # cat /sys/kernel/debug/dmaengine
> dma0 (285c0000.dma-controller): number of channels: 96
>
> dma1 (31150000.dma-controller): number of channels: 267
> dma1chan0 | 2b00000.mcasp:tx
> dma1chan1 | 2b00000.mcasp:rx
> dma1chan2 | in-use
> dma1chan3 | in-use
> dma1chan4 | in-use
> dma1chan5 | in-use
>
> With my current .dbg_show implementation for k3-udma:
> # cat /sys/kernel/debug/dmaengine
> dma0 (285c0000.dma-controller): number of channels: 96
>
> dma1 (31150000.dma-controller): number of channels: 267
> dma1chan0 | 2b00000.mcasp:tx (MEM_TO_DEV, tchan8 [0x1008 -> 0xc400], PDMA, TR mode)
> dma1chan1 | 2b00000.mcasp:rx (DEV_TO_MEM, rchan8 [0x4400 -> 0x9008], PDMA, TR mode)
> dma1chan2 | in-use (MEM_TO_MEM, chan2 pair [0x1002 -> 0x9002], PSI-L Native, TR mode)
> dma1chan3 | in-use (MEM_TO_MEM, chan3 pair [0x1003 -> 0x9003], PSI-L Native, TR mode)
> dma1chan4 | in-use (MEM_TO_MEM, chan4 pair [0x1004 -> 0x9004], PSI-L Native, TR mode)
> dma1chan5 | in-use (MEM_TO_MEM, chan5 pair [0x1005 -> 0x9005], PSI-L Native, TR mode)
>
> For me this makes a huge difference.
Ok
> >> +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
> >> +
> >> +static int __init dmaengine_debugfs_init(void)
> >> +{
> >> + /* /sys/kernel/debug/dmaengine */
> >> + debugfs_create_file("dmaengine", 0444, NULL, NULL,
> >> + &dmaengine_debugfs_fops);
> >
> > Should we add a directory? That way we can keep adding stuff into that
> > one
>
> and have this file as 'summary' underneath?
Correct
> I like the fact hat I can get all the information via one file.
> Saves a lot of time (and explaining to users) on finding the correct
> one to cat...
But am sure we can come with more data to show, so having a directory
helps :)
--
~Vinod
Hi Vinod,
On 28/02/2020 6.47, Vinod Koul wrote:
> Hi Peter,
>
> On 26-02-20, 14:10, Peter Ujfalusi wrote:
>
>>> do we really want a custom dbg_show()..? Drivers can add their own
>>> files...
>>
>> They could do that already ;)
>>
>> With the custom dbg_show() DMA drivers can save on the surrounding
>> code and just fill in the information regarding to their HW.
>> Again, on am654 the default information is:
>> # cat /sys/kernel/debug/dmaengine
>> dma0 (285c0000.dma-controller): number of channels: 96
>>
>> dma1 (31150000.dma-controller): number of channels: 267
>> dma1chan0 | 2b00000.mcasp:tx
>> dma1chan1 | 2b00000.mcasp:rx
>> dma1chan2 | in-use
>> dma1chan3 | in-use
>> dma1chan4 | in-use
>> dma1chan5 | in-use
>>
>> With my current .dbg_show implementation for k3-udma:
>> # cat /sys/kernel/debug/dmaengine
>> dma0 (285c0000.dma-controller): number of channels: 96
>>
>> dma1 (31150000.dma-controller): number of channels: 267
>> dma1chan0 | 2b00000.mcasp:tx (MEM_TO_DEV, tchan8 [0x1008 -> 0xc400], PDMA, TR mode)
>> dma1chan1 | 2b00000.mcasp:rx (DEV_TO_MEM, rchan8 [0x4400 -> 0x9008], PDMA, TR mode)
>> dma1chan2 | in-use (MEM_TO_MEM, chan2 pair [0x1002 -> 0x9002], PSI-L Native, TR mode)
>> dma1chan3 | in-use (MEM_TO_MEM, chan3 pair [0x1003 -> 0x9003], PSI-L Native, TR mode)
>> dma1chan4 | in-use (MEM_TO_MEM, chan4 pair [0x1004 -> 0x9004], PSI-L Native, TR mode)
>> dma1chan5 | in-use (MEM_TO_MEM, chan5 pair [0x1005 -> 0x9005], PSI-L Native, TR mode)
>>
>> For me this makes a huge difference.
>
> Ok
>
>>>> +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
>>>> +
>>>> +static int __init dmaengine_debugfs_init(void)
>>>> +{
>>>> + /* /sys/kernel/debug/dmaengine */
>>>> + debugfs_create_file("dmaengine", 0444, NULL, NULL,
>>>> + &dmaengine_debugfs_fops);
>>>
>>> Should we add a directory? That way we can keep adding stuff into that
>>> one
>>
>> and have this file as 'summary' underneath?
>
> Correct
/sys/kernel/debug/dmaengine/summary, right?
>> I like the fact hat I can get all the information via one file.
>> Saves a lot of time (and explaining to users) on finding the correct
>> one to cat...
>
> But am sure we can come with more data to show, so having a directory
> helps :)
OK, so we need to store the dbgfs rootdir and add an API so DMA drivers
can get the dentry of it, so they can implement their custom
files/directories underneath.
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On 28-02-20, 12:01, Peter Ujfalusi wrote:
> Hi Vinod,
>
> On 28/02/2020 6.47, Vinod Koul wrote:
> > Hi Peter,
> >
> > On 26-02-20, 14:10, Peter Ujfalusi wrote:
> >
> >>> do we really want a custom dbg_show()..? Drivers can add their own
> >>> files...
> >>
> >> They could do that already ;)
> >>
> >> With the custom dbg_show() DMA drivers can save on the surrounding
> >> code and just fill in the information regarding to their HW.
> >> Again, on am654 the default information is:
> >> # cat /sys/kernel/debug/dmaengine
> >> dma0 (285c0000.dma-controller): number of channels: 96
> >>
> >> dma1 (31150000.dma-controller): number of channels: 267
> >> dma1chan0 | 2b00000.mcasp:tx
> >> dma1chan1 | 2b00000.mcasp:rx
> >> dma1chan2 | in-use
> >> dma1chan3 | in-use
> >> dma1chan4 | in-use
> >> dma1chan5 | in-use
> >>
> >> With my current .dbg_show implementation for k3-udma:
> >> # cat /sys/kernel/debug/dmaengine
> >> dma0 (285c0000.dma-controller): number of channels: 96
> >>
> >> dma1 (31150000.dma-controller): number of channels: 267
> >> dma1chan0 | 2b00000.mcasp:tx (MEM_TO_DEV, tchan8 [0x1008 -> 0xc400], PDMA, TR mode)
> >> dma1chan1 | 2b00000.mcasp:rx (DEV_TO_MEM, rchan8 [0x4400 -> 0x9008], PDMA, TR mode)
> >> dma1chan2 | in-use (MEM_TO_MEM, chan2 pair [0x1002 -> 0x9002], PSI-L Native, TR mode)
> >> dma1chan3 | in-use (MEM_TO_MEM, chan3 pair [0x1003 -> 0x9003], PSI-L Native, TR mode)
> >> dma1chan4 | in-use (MEM_TO_MEM, chan4 pair [0x1004 -> 0x9004], PSI-L Native, TR mode)
> >> dma1chan5 | in-use (MEM_TO_MEM, chan5 pair [0x1005 -> 0x9005], PSI-L Native, TR mode)
> >>
> >> For me this makes a huge difference.
> >
> > Ok
> >
> >>>> +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs);
> >>>> +
> >>>> +static int __init dmaengine_debugfs_init(void)
> >>>> +{
> >>>> + /* /sys/kernel/debug/dmaengine */
> >>>> + debugfs_create_file("dmaengine", 0444, NULL, NULL,
> >>>> + &dmaengine_debugfs_fops);
> >>>
> >>> Should we add a directory? That way we can keep adding stuff into that
> >>> one
> >>
> >> and have this file as 'summary' underneath?
> >
> > Correct
>
> /sys/kernel/debug/dmaengine/summary, right?
Yup!
>
> >> I like the fact hat I can get all the information via one file.
> >> Saves a lot of time (and explaining to users) on finding the correct
> >> one to cat...
> >
> > But am sure we can come with more data to show, so having a directory
> > helps :)
>
> OK, so we need to store the dbgfs rootdir and add an API so DMA drivers
> can get the dentry of it, so they can implement their custom
> files/directories underneath.
Correct
--
~Vinod