[PATCH v2 1/1] serdev: Replace poll loop by readx_poll_timeout() macro

[PATCH v2 1/1] serdev: Replace poll loop by readx_poll_timeout() macro

[Andy Shevchenko]

The readx_poll_timeout() consolidates the necessary code under
macro. Replace current code with it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: dropped TODO: in the Subject line
 include/linux/serdev.h | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 66f624fc618c..69d9c3188065 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -7,9 +7,11 @@
 
 #include <linux/types.h>
 #include <linux/device.h>
+#include <linux/iopoll.h>
 #include <linux/uaccess.h>
 #include <linux/termios.h>
 #include <linux/delay.h>
+#include <vdso/time64.h>
 
 struct serdev_controller;
 struct serdev_device;
@@ -279,18 +281,10 @@ static inline bool serdev_device_get_cts(struct serdev_device *serdev)
 
 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
 {
-	unsigned long timeout;
 	bool signal;
 
-	timeout = jiffies + msecs_to_jiffies(timeout_ms);
-	while (time_is_after_jiffies(timeout)) {
-		signal = serdev_device_get_cts(serdev);
-		if (signal == state)
-			return 0;
-		usleep_range(1000, 2000);
-	}
-
-	return -ETIMEDOUT;
+	return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
+				  2000, timeout_ms * USEC_PER_MSEC);
 }
 
 static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
-- 
2.35.1

Re: [PATCH v2 1/1] serdev: Replace poll loop by readx_poll_timeout() macro

[Greg Kroah-Hartman]

On Fri, Sep 23, 2022 at 08:10:48PM +0300, Andy Shevchenko wrote:
> The readx_poll_timeout() consolidates the necessary code under
> macro. Replace current code with it.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> v2: dropped TODO: in the Subject line
>  include/linux/serdev.h | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/serdev.h b/include/linux/serdev.h
> index 66f624fc618c..69d9c3188065 100644
> --- a/include/linux/serdev.h
> +++ b/include/linux/serdev.h
> @@ -7,9 +7,11 @@
>  
>  #include <linux/types.h>
>  #include <linux/device.h>
> +#include <linux/iopoll.h>
>  #include <linux/uaccess.h>
>  #include <linux/termios.h>
>  #include <linux/delay.h>
> +#include <vdso/time64.h>

Ick, just for USEC_PER_MSEC?  That should be in units.h, not burried in
a vdso-only .h file.  This feels wrong, sorry.

greg k-h

Re: [PATCH v2 1/1] serdev: Replace poll loop by readx_poll_timeout() macro

[Andy Shevchenko]

On Sat, Sep 24, 2022 at 01:57:29PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Sep 23, 2022 at 08:10:48PM +0300, Andy Shevchenko wrote:
> > The readx_poll_timeout() consolidates the necessary code under
> > macro. Replace current code with it.

...

> > +#include <vdso/time64.h>
> 
> Ick, just for USEC_PER_MSEC?  That should be in units.h, not burried in
> a vdso-only .h file.  This feels wrong, sorry.

Why are you asking me about this? It was not my choice and it was made
a couple of years ago (see [1]).

As a solution I can just drop using that constant in v3.

[1]: b72a9c5e023b ("linux/time64.h: Extract common header for vDSO")


-- 
With Best Regards,
Andy Shevchenko