[PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[Shengzhou Liu]

Currently get_phy_c45_ids() driver assumes that device zero is reserved and
doesn't probe c45 device which has zero device address. The driver only
probes c45 phy with non-zero device address by code:
for(i = 1; i < num_ids && c45_ids->devices_in_package == 0; i++)

This patch updates the driver to support those c45 phy which has special zero
device address(e.g. the device address is zero on Cortina CS4315/CS4340 10G
PHY, 'i' must be zero to have it work).

We should first probe non-zero devices, if not found, then probe device zero.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
---
v3: refined commit messages.
v2: refined to reuse code.

 drivers/net/phy/phy_device.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index cfb5110..88f1d38 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -226,13 +226,11 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 	int i, reg_addr;
 	const int num_ids = ARRAY_SIZE(c45_ids->device_ids);
 
-	/* Find first non-zero Devices In package.  Device
-	 * zero is reserved, so don't probe it.
-	 */
+	/* Find first non-zero Devices In package */
 	for (i = 1;
 	     i < num_ids && c45_ids->devices_in_package == 0;
 	     i++) {
-		reg_addr = MII_ADDR_C45 | i << 16 | 6;
+retry:		reg_addr = MII_ADDR_C45 | i << 16 | 6;
 		phy_reg = mdiobus_read(bus, addr, reg_addr);
 		if (phy_reg < 0)
 			return -EIO;
@@ -244,12 +242,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 			return -EIO;
 		c45_ids->devices_in_package |= (phy_reg & 0xffff);
 
-		/* If mostly Fs, there is no device there,
-		 * let's get out of here.
-		 */
 		if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
-			*phy_id = 0xffffffff;
-			return 0;
+			if (i) {
+				/*  If mostly Fs, there is no non-zero device
+				 *  found, then let's continue to probe more
+				 *  for special device which has zero device
+				 *  address, thus set i = 0 to try again.
+				 */
+				i = 0;
+				goto retry;
+			} else {
+				/* no device there, let's get out of here */
+				*phy_id = 0xffffffff;
+				return 0;
+			}
 		}
 	}
 
-- 
1.8.0

Re: [PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[David Miller]

From: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Date: Wed, 28 May 2014 16:54:36 +0800

> -	/* Find first non-zero Devices In package.  Device
> -	 * zero is reserved, so don't probe it.
> -	 */
> +	/* Find first non-zero Devices In package */
>  	for (i = 1;
>  	     i < num_ids && c45_ids->devices_in_package == 0;
>  	     i++) {
 ...
> -			return 0;
> +			if (i) {

It makes no sense to test 'i' for zero vs. non-zero until the looping
construct it is contained within can actually hit a zero value.

It cannot currently, and adding such a check here makes the code
confusing.

I'm not applying this, sorry.

Re: [PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[David Miller]

From: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Date: Fri, 26 Jun 2015 17:58:52 +0800

> As some C45 10G PHYs(e.g. Cortina CS4315/CS4340 PHY) have
> zero Devices In package, current driver can't get correct
> devices_in_package value by non-zero Devices In package.
> so let's probe more with zero Devices In package to support
> more C45 PHYs.
> 
> Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>

Applied.

Re: [PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[Florian Fainelli]

On 26/06/15 02:58, Shengzhou Liu wrote:
> As some C45 10G PHYs(e.g. Cortina CS4315/CS4340 PHY) have
> zero Devices In package, current driver can't get correct
> devices_in_package value by non-zero Devices In package.
> so let's probe more with zero Devices In package to support
> more C45 PHYs.

This looks better to me now:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> 
> Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
> ---
> v3: restructure the loop to probe naturally.  
> v2: use MDIO_DEVS1 and MDIO_DEVS2 instead of constant '6', '5'
> 
>  drivers/net/phy/phy_device.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index bdfe51f..3e90037 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -230,7 +230,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
>  	for (i = 1;
>  	     i < num_ids && c45_ids->devices_in_package == 0;
>  	     i++) {
> -		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
> +retry:		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
>  		phy_reg = mdiobus_read(bus, addr, reg_addr);
>  		if (phy_reg < 0)
>  			return -EIO;
> @@ -242,12 +242,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
>  			return -EIO;
>  		c45_ids->devices_in_package |= (phy_reg & 0xffff);
>  
> -		/* If mostly Fs, there is no device there,
> -		 * let's get out of here.
> -		 */
>  		if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
> -			*phy_id = 0xffffffff;
> -			return 0;
> +			if (i) {
> +				/*  If mostly Fs, there is no device there,
> +				 *  then let's continue to probe more, as some
> +				 *  10G PHYs have zero Devices In package,
> +				 *  e.g. Cortina CS4315/CS4340 PHY.
> +				 */
> +				i = 0;
> +				goto retry;
> +			} else {
> +				/* no device there, let's get out of here */
> +				*phy_id = 0xffffffff;
> +				return 0;
> +			}
>  		}
>  	}
>  
> 


-- 
Florian

[PATCH v3] net/phy: tune get_phy_c45_ids to support more c45 phy

[Shengzhou Liu]

As some C45 10G PHYs(e.g. Cortina CS4315/CS4340 PHY) have
zero Devices In package, current driver can't get correct
devices_in_package value by non-zero Devices In package.
so let's probe more with zero Devices In package to support
more C45 PHYs.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
---
v3: restructure the loop to probe naturally.  
v2: use MDIO_DEVS1 and MDIO_DEVS2 instead of constant '6', '5'

 drivers/net/phy/phy_device.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index bdfe51f..3e90037 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -230,7 +230,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 	for (i = 1;
 	     i < num_ids && c45_ids->devices_in_package == 0;
 	     i++) {
-		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
+retry:		reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
 		phy_reg = mdiobus_read(bus, addr, reg_addr);
 		if (phy_reg < 0)
 			return -EIO;
@@ -242,12 +242,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
 			return -EIO;
 		c45_ids->devices_in_package |= (phy_reg & 0xffff);
 
-		/* If mostly Fs, there is no device there,
-		 * let's get out of here.
-		 */
 		if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
-			*phy_id = 0xffffffff;
-			return 0;
+			if (i) {
+				/*  If mostly Fs, there is no device there,
+				 *  then let's continue to probe more, as some
+				 *  10G PHYs have zero Devices In package,
+				 *  e.g. Cortina CS4315/CS4340 PHY.
+				 */
+				i = 0;
+				goto retry;
+			} else {
+				/* no device there, let's get out of here */
+				*phy_id = 0xffffffff;
+				return 0;
+			}
 		}
 	}
 
-- 
2.1.0.27.g96db324