2022-11-17 14:30:39

by Charles Keepax

Subject: [PATCH v2 3/4] soundwire: debugfs: Switch to sdw_read_no_pm

It is rather inefficient to be constantly playing with the runtime
PM reference for each individual register, switch to holding a PM
runtime reference across the whole register output.

Signed-off-by: Charles Keepax <[email protected]>
---

Changes since v1:
- Reworded commit message

drivers/soundwire/debugfs.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index 49900cd207bc7..0718e9cda138a 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -4,6 +4,7 @@
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/mod_devicetable.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_registers.h>
@@ -35,7 +36,7 @@ static ssize_t sdw_sprintf(struct sdw_slave *slave,
{
int value;

- value = sdw_read(slave, reg);
+ value = sdw_read_no_pm(slave, reg);

if (value < 0)
return scnprintf(buf + pos, RD_BUF - pos, "%3x\tXX\n", reg);
@@ -55,6 +56,10 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
if (!buf)
return -ENOMEM;

+ ret = pm_runtime_resume_and_get(&slave->dev);
+ if (ret < 0 && ret != -EACCES)
+ return ret;
+
ret = scnprintf(buf, RD_BUF, "Register Value\n");

/* DP0 non-banked registers */
@@ -112,6 +117,10 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
}

seq_printf(s_file, "%s", buf);
+
+ pm_runtime_mark_last_busy(&slave->dev);
+ pm_runtime_put(&slave->dev);
+
kfree(buf);

return 0;
--
2.30.2

2022-11-17 15:10:38

by Pierre-Louis Bossart

Subject: Re: [PATCH v2 3/4] soundwire: debugfs: Switch to sdw_read_no_pm

On 11/17/22 08:17, Charles Keepax wrote:
> It is rather inefficient to be constantly playing with the runtime
> PM reference for each individual register, switch to holding a PM
> runtime reference across the whole register output.
>
> Signed-off-by: Charles Keepax <[email protected]>

Reviewed-by: Pierre-Louis Bossart <[email protected]>

> ---
>
> Changes since v1:
> - Reworded commit message
>
> drivers/soundwire/debugfs.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
> index 49900cd207bc7..0718e9cda138a 100644
> --- a/drivers/soundwire/debugfs.c
> +++ b/drivers/soundwire/debugfs.c
> @@ -4,6 +4,7 @@
> #include <linux/device.h>
> #include <linux/debugfs.h>
> #include <linux/mod_devicetable.h>
> +#include <linux/pm_runtime.h>
> #include <linux/slab.h>
> #include <linux/soundwire/sdw.h>
> #include <linux/soundwire/sdw_registers.h>
> @@ -35,7 +36,7 @@ static ssize_t sdw_sprintf(struct sdw_slave *slave,
> {
> int value;
>
> - value = sdw_read(slave, reg);
> + value = sdw_read_no_pm(slave, reg);
>
> if (value < 0)
> return scnprintf(buf + pos, RD_BUF - pos, "%3x\tXX\n", reg);
> @@ -55,6 +56,10 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
> if (!buf)
> return -ENOMEM;
>
> + ret = pm_runtime_resume_and_get(&slave->dev);
> + if (ret < 0 && ret != -EACCES)
> + return ret;
> +
> ret = scnprintf(buf, RD_BUF, "Register Value\n");
>
> /* DP0 non-banked registers */
> @@ -112,6 +117,10 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
> }
>
> seq_printf(s_file, "%s", buf);
> +
> + pm_runtime_mark_last_busy(&slave->dev);
> + pm_runtime_put(&slave->dev);
> +
> kfree(buf);
>
> return 0;