[PATCH net-next v3 0/7] introduce read_poll_timeout

[PATCH net-next v3 0/7] introduce read_poll_timeout

[Dejin Zheng]

This patch sets is introduce read_poll_timeout macro, it is an extension
of readx_poll_timeout macro. the accessor function op just supports only
one parameter in the readx_poll_timeout macro, but this macro can
supports multiple variable parameters for it. so functions like
phy_read(struct phy_device *phydev, u32 regnum) and
phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum) can
use this poll timeout framework.

the first patch introduce read_poll_timeout macro, and the second patch
redefined readx_poll_timeout macro by read_poll_timeout(), and the other
patches are examples using read_poll_timeout macro.

v2 -> v3:
	- modify the parameter order of newly added functions.
	  phy_read_mmd_poll_timeout(val, cond, sleep_us, timeout_us, \
				     phydev, devaddr, regnum)
				||
				\/
	  phy_read_mmd_poll_timeout(phydev, devaddr regnum, val, cond, \
				    sleep_us, timeout_us)

	  phy_read_poll_timeout(val, cond, sleep_us, timeout_us, \
				phydev, regnum)
				||
				\/
	  phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, \
				timeout_us)


v1 -> v2:
	- passed a phydev, device address and a reg to replace args...
	  parameter in phy_read_mmd_poll_timeout() by Andrew Lunn 's
	  suggestion in patch 3. Andrew Lunn <andrew@lunn.ch>, Thanks
	  very much for your help!
	- also in patch 3, handle phy_read_mmd return an error(the return
	  value < 0) in phy_read_mmd_poll_timeout(). Thanks Andrew
	  again.
	- in patch 6, pass a phydev and a reg to replace args...
	  parameter in phy_read_poll_timeout(), and also handle the
	  phy_read() function's return error.



Dejin Zheng (7):
  iopoll: introduce read_poll_timeout macro
  iopoll: redefined readx_poll_timeout macro to simplify the code
  net: phy: introduce phy_read_mmd_poll_timeout macro
  net: phy: bcm84881: use phy_read_mmd_poll_timeout() to simplify the
    code
  net: phy: aquantia: use phy_read_mmd_poll_timeout() to simplify the
    code
  net: phy: introduce phy_read_poll_timeout macro
  net: phy: use phy_read_poll_timeout() to simplify the code

 drivers/net/phy/aquantia_main.c | 13 ++++--------
 drivers/net/phy/bcm84881.c      | 27 ++++---------------------
 drivers/net/phy/phy_device.c    | 16 ++++-----------
 include/linux/iopoll.h          | 36 ++++++++++++++++++++++++++-------
 include/linux/phy.h             | 27 +++++++++++++++++++++++++
 5 files changed, 68 insertions(+), 51 deletions(-)

-- 
2.25.0

[PATCH net-next v3 1/7] iopoll: introduce read_poll_timeout macro

[Dejin Zheng]

this macro is an extension of readx_poll_timeout macro. the accessor
function op just supports only one parameter in the readx_poll_timeout
macro, but this macro can supports multiple variable parameters for
it. so functions like phy_read(struct phy_device *phydev, u32 regnum)
and phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum) can
also use this poll timeout framework.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	no changed
v1 -> v2:
	no changed

 include/linux/iopoll.h | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
index 35e15dfd4155..7d44a2e20267 100644
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -13,6 +13,46 @@
 #include <linux/errno.h>
 #include <linux/io.h>
 
+/**
+ * read_poll_timeout - Periodically poll an address until a condition is
+ *			met or a timeout occurs
+ * @op: accessor function (takes @args as its arguments)
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @sleep_us: Maximum time to sleep between reads in us (0
+ *            tight-loops).  Should be less than ~20ms since usleep_range
+ *            is used (see Documentation/timers/timers-howto.rst).
+ * @timeout_us: Timeout in us, 0 means never timeout
+ * @args: arguments for @op poll
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @args is stored in @val. Must not
+ * be called from atomic context if sleep_us or timeout_us are used.
+ *
+ * When available, you'll probably want to use one of the specialized
+ * macros defined below rather than this macro directly.
+ */
+#define read_poll_timeout(op, val, cond, sleep_us, timeout_us, args...)	\
+({ \
+	u64 __timeout_us = (timeout_us); \
+	unsigned long __sleep_us = (sleep_us); \
+	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
+	might_sleep_if((__sleep_us) != 0); \
+	for (;;) { \
+		(val) = op(args); \
+		if (cond) \
+			break; \
+		if (__timeout_us && \
+		    ktime_compare(ktime_get(), __timeout) > 0) { \
+			(val) = op(args); \
+			break; \
+		} \
+		if (__sleep_us) \
+			usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
 /**
  * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
  * @op: accessor function (takes @addr as its only argument)
-- 
2.25.0

[PATCH net-next v3 2/7] iopoll: redefined readx_poll_timeout macro to simplify the code

[Dejin Zheng]

redefined readx_poll_timeout macro by read_poll_timeout to
simplify the code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	no changed
v1 -> v2:
	no changed

 include/linux/iopoll.h | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
index 7d44a2e20267..29c016cd6249 100644
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -72,25 +72,7 @@
  * macros defined below rather than this macro directly.
  */
 #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us)	\
-({ \
-	u64 __timeout_us = (timeout_us); \
-	unsigned long __sleep_us = (sleep_us); \
-	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
-	might_sleep_if((__sleep_us) != 0); \
-	for (;;) { \
-		(val) = op(addr); \
-		if (cond) \
-			break; \
-		if (__timeout_us && \
-		    ktime_compare(ktime_get(), __timeout) > 0) { \
-			(val) = op(addr); \
-			break; \
-		} \
-		if (__sleep_us) \
-			usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
-	} \
-	(cond) ? 0 : -ETIMEDOUT; \
-})
+	read_poll_timeout(op, val, cond, sleep_us, timeout_us, addr)
 
 /**
  * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
-- 
2.25.0

[PATCH net-next v3 3/7] net: phy: introduce phy_read_mmd_poll_timeout macro

[Dejin Zheng]

it is sometimes necessary to poll a phy register by phy_read_mmd()
function until its value satisfies some condition. introduce
phy_read_mmd_poll_timeout() macros that do this.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- modify the parameter order of newly added functions.
	  phy_read_mmd_poll_timeout(val, cond, sleep_us, timeout_us, \
				     phydev, devaddr, regnum)
				||
				\/
	  phy_read_mmd_poll_timeout(phydev, devaddr regnum, val, cond, \
				    sleep_us, timeout_us)
v1 -> v2:
	- passed a phydev, device address and a reg to replace args...
	  parameter in phy_read_mmd_poll_timeout() by Andrew Lunn 's
	  suggestion. Andrew Lunn <andrew@lunn.ch>, Thanks very much for
	  your help!
	- handle phy_read_mmd return an error(the return value < 0) in
	  phy_read_mmd_poll_timeout(). Thanks Andrew again.


 include/linux/phy.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 36d9dea04016..29718865242d 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -24,6 +24,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/u64_stats_sync.h>
 #include <linux/irqreturn.h>
+#include <linux/iopoll.h>
 
 #include <linux/atomic.h>
 
@@ -784,6 +785,19 @@ static inline int __phy_modify_changed(struct phy_device *phydev, u32 regnum,
  */
 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum);
 
+#define phy_read_mmd_poll_timeout(phydev, devaddr, regnum, val, cond, \
+				  sleep_us, timeout_us) \
+({ \
+	int ret = 0; \
+	ret = read_poll_timeout(phy_read_mmd, val, cond || val < 0, sleep_us, \
+				timeout_us, phydev, devaddr, regnum); \
+	if (val <  0) \
+		ret = val; \
+	if (ret) \
+		phydev_err(phydev, "%s failed: %d\n", __func__, ret); \
+	ret; \
+})
+
 /**
  * __phy_read_mmd - Convenience function for reading a register
  * from an MMD on a given PHY.
-- 
2.25.0

[PATCH net-next v3 4/7] net: phy: bcm84881: use phy_read_mmd_poll_timeout() to simplify the code

[Dejin Zheng]

use phy_read_mmd_poll_timeout() to replace the poll codes for
simplify the code in bcm84881_wait_init() function.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- adapt to it after modifying the parameter order of the
	  newly added function
v1 -> v2:
	- remove the handle of phy_read_mmd's return error.

 drivers/net/phy/bcm84881.c | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/drivers/net/phy/bcm84881.c b/drivers/net/phy/bcm84881.c
index 14d55a77eb28..b70be775909c 100644
--- a/drivers/net/phy/bcm84881.c
+++ b/drivers/net/phy/bcm84881.c
@@ -22,30 +22,11 @@ enum {
 
 static int bcm84881_wait_init(struct phy_device *phydev)
 {
-	unsigned int tries = 20;
-	int ret, val;
-
-	do {
-		val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1);
-		if (val < 0) {
-			ret = val;
-			break;
-		}
-		if (!(val & MDIO_CTRL1_RESET)) {
-			ret = 0;
-			break;
-		}
-		if (!--tries) {
-			ret = -ETIMEDOUT;
-			break;
-		}
-		msleep(100);
-	} while (1);
+	int val;
 
-	if (ret)
-		phydev_err(phydev, "%s failed: %d\n", __func__, ret);
-
-	return ret;
+	return phy_read_mmd_poll_timeout(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1,
+					 val, !(val & MDIO_CTRL1_RESET),
+					 100000, 2000000);
 }
 
 static int bcm84881_config_init(struct phy_device *phydev)
-- 
2.25.0

[PATCH net-next v3 5/7] net: phy: aquantia: use phy_read_mmd_poll_timeout() to simplify the code

[Dejin Zheng]

use phy_read_mmd_poll_timeout() to replace the poll codes for
simplify the code in aqr107_wait_reset_complete() function.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- adapt to it after modifying the parameter order of the
	  newly added function
v1 -> v2:
	- remove the handle of phy_read_mmd's return error.

 drivers/net/phy/aquantia_main.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/net/phy/aquantia_main.c b/drivers/net/phy/aquantia_main.c
index 31927b2c7d5a..db3e20938729 100644
--- a/drivers/net/phy/aquantia_main.c
+++ b/drivers/net/phy/aquantia_main.c
@@ -451,16 +451,11 @@ static int aqr107_set_tunable(struct phy_device *phydev,
  */
 static int aqr107_wait_reset_complete(struct phy_device *phydev)
 {
-	int val, retries = 100;
-
-	do {
-		val = phy_read_mmd(phydev, MDIO_MMD_VEND1, VEND1_GLOBAL_FW_ID);
-		if (val < 0)
-			return val;
-		msleep(20);
-	} while (!val && --retries);
+	int val;
 
-	return val ? 0 : -ETIMEDOUT;
+	return phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1,
+					 VEND1_GLOBAL_FW_ID, val,
+					 val != 0, 20000, 2000000);
 }
 
 static void aqr107_chip_info(struct phy_device *phydev)
-- 
2.25.0

[PATCH net-next v3 6/7] net: phy: introduce phy_read_poll_timeout macro

[Dejin Zheng]

it is sometimes necessary to poll a phy register by phy_read()
function until its value satisfies some condition. introduce
phy_read_poll_timeout() macros that do this.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- modify the parameter order of newly added functions.
	  phy_read_poll_timeout(val, cond, sleep_us, timeout_us, \
				phydev, regnum)
				||
				\/
	  phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, \
				timeout_us)
v1 -> v2:
	- pass a phydev and a regnum to replace args... parameter in
	  the phy_read_poll_timeout(), and also handle the
	  phy_read() function's return error.
 
 include/linux/phy.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 29718865242d..a23d6caf5c2c 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -714,6 +714,19 @@ static inline int phy_read(struct phy_device *phydev, u32 regnum)
 	return mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, regnum);
 }
 
+#define phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, timeout_us) \
+({ \
+	int ret = 0; \
+	ret = read_poll_timeout(phy_read, val, cond || val < 0, sleep_us, \
+				timeout_us, phydev, regnum); \
+	if (val <  0) \
+		ret = val; \
+	if (ret) \
+		phydev_err(phydev, "%s failed: %d\n", __func__, ret); \
+	ret; \
+})
+
+
 /**
  * __phy_read - convenience function for reading a given PHY register
  * @phydev: the phy_device struct
-- 
2.25.0

[PATCH net-next v3 7/7] net: phy: use phy_read_poll_timeout() to simplify the code

[Dejin Zheng]

use phy_read_poll_timeout() to replace the poll codes for
simplify the code in phy_poll_reset() function.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- adapt to it after modifying the parameter order of the
	  newly added function
v1 -> v2:
	- remove the handle of phy_read()'s return error.

 drivers/net/phy/phy_device.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index a585faf8b844..cfe7aae35084 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1059,23 +1059,15 @@ EXPORT_SYMBOL(phy_disconnect);
 static int phy_poll_reset(struct phy_device *phydev)
 {
 	/* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
-	unsigned int retries = 12;
-	int ret;
-
-	do {
-		msleep(50);
-		ret = phy_read(phydev, MII_BMCR);
-		if (ret < 0)
-			return ret;
-	} while (ret & BMCR_RESET && --retries);
-	if (ret & BMCR_RESET)
-		return -ETIMEDOUT;
+	int ret, val;
 
+	ret = phy_read_poll_timeout(phydev, MII_BMCR, val, !(val & BMCR_RESET),
+				    50000, 600000);
 	/* Some chips (smsc911x) may still need up to another 1ms after the
 	 * BMCR_RESET bit is cleared before they are usable.
 	 */
 	msleep(1);
-	return 0;
+	return ret;
 }
 
 int phy_init_hw(struct phy_device *phydev)
-- 
2.25.0

Re: [PATCH net-next v3 7/7] net: phy: use phy_read_poll_timeout() to simplify the code

[Florian Fainelli]

On 3/21/2020 7:48 PM, Dejin Zheng wrote:
> use phy_read_poll_timeout() to replace the poll codes for
> simplify the code in phy_poll_reset() function.
> 
> Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> ---
> v2 -> v3:
> 	- adapt to it after modifying the parameter order of the
> 	  newly added function
> v1 -> v2:
> 	- remove the handle of phy_read()'s return error.
> 
>  drivers/net/phy/phy_device.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index a585faf8b844..cfe7aae35084 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1059,23 +1059,15 @@ EXPORT_SYMBOL(phy_disconnect);
>  static int phy_poll_reset(struct phy_device *phydev)
>  {
>  	/* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
> -	unsigned int retries = 12;
> -	int ret;
> -
> -	do {
> -		msleep(50);
> -		ret = phy_read(phydev, MII_BMCR);

You are doing some subtle changes here, the sleep used to be *before*
the read of BMCR and now it will be *after*. If there were PHY devices
that required 50ms at least, but would incorrectly return that
BMCR_RESET is cleared *before* 50ms, then we would be breaking those.

I would recommend we drop this patch for now, the rest looks good to me
though.
-- 
Florian

Re: [PATCH net-next v3 7/7] net: phy: use phy_read_poll_timeout() to simplify the code

[Dejin Zheng]

On Sat, Mar 21, 2020 at 07:57:11PM -0700, Florian Fainelli wrote:
> 
> 
> On 3/21/2020 7:48 PM, Dejin Zheng wrote:
> > use phy_read_poll_timeout() to replace the poll codes for
> > simplify the code in phy_poll_reset() function.
> > 
> > Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> > ---
> > v2 -> v3:
> > 	- adapt to it after modifying the parameter order of the
> > 	  newly added function
> > v1 -> v2:
> > 	- remove the handle of phy_read()'s return error.
> > 
> >  drivers/net/phy/phy_device.c | 16 ++++------------
> >  1 file changed, 4 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> > index a585faf8b844..cfe7aae35084 100644
> > --- a/drivers/net/phy/phy_device.c
> > +++ b/drivers/net/phy/phy_device.c
> > @@ -1059,23 +1059,15 @@ EXPORT_SYMBOL(phy_disconnect);
> >  static int phy_poll_reset(struct phy_device *phydev)
> >  {
> >  	/* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
> > -	unsigned int retries = 12;
> > -	int ret;
> > -
> > -	do {
> > -		msleep(50);
> > -		ret = phy_read(phydev, MII_BMCR);
> 
> You are doing some subtle changes here, the sleep used to be *before*
> the read of BMCR and now it will be *after*. If there were PHY devices
> that required 50ms at least, but would incorrectly return that
> BMCR_RESET is cleared *before* 50ms, then we would be breaking those.
> 
> I would recommend we drop this patch for now, the rest looks good to me
> though.

Hi Florian��

Thanks very much for your comments, I will drop this patch, and can I get
your ack/reviewed-by for the rest patches? thanks again!

BR,
dejin

> -- 
> Florian