[PATCH 0/3] net: davinci_emac: fix suspend/resume (both a regression and a common clk problem)

[PATCH 0/3] net: davinci_emac: fix suspend/resume (both a regression and a common clk problem)

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Earlier today I sent the first patch as a solution to a regression
introduced during the v4.16 merge window, but after testing David's
common clock series on top of 4.18-rc1 + this patch it turned out that
the problem persisted.

This is a follow-up containing the regression fix and two additional
patches that make suspend/resume work with David's changes.

Bartosz Golaszewski (3):
  net: ethernet: fix suspend/resume in davinci_emac
  net: phy: set the of_node in the mdiodev's struct device
  net: davinci_emac: match the mdio device against its compatible if
    possible

 drivers/net/ethernet/ti/davinci_emac.c | 19 +++++++++++++++++--
 drivers/net/phy/phy_device.c           |  1 +
 2 files changed, 18 insertions(+), 2 deletions(-)

-- 
2.17.1

[PATCH 1/3] net: ethernet: fix suspend/resume in davinci_emac

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This patch reverts commit 3243ff2a05ec ("net: ethernet: davinci_emac:
Deduplicate bus_find_device() by name matching") and adds a comment
which should stop anyone from reintroducing the same "fix" in the future.

We can't use bus_find_device_by_name() here because the device name is
not guaranteed to be 'davinci_mdio'. On some systems it can be
'davinci_mdio.0' so we need to use strncmp() against the first part of
the string to correctly match it.

Fixes: 3243ff2a05ec ("net: ethernet: davinci_emac: Deduplicate bus_find_device() by name matching")
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/net/ethernet/ti/davinci_emac.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 06d7c9e4dcda..a1a6445b5a7e 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1385,6 +1385,11 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
 		return -EOPNOTSUPP;
 }
 
+static int match_first_device(struct device *dev, void *data)
+{
+	return !strncmp(dev_name(dev), "davinci_mdio", 12);
+}
+
 /**
  * emac_dev_open - EMAC device open
  * @ndev: The DaVinci EMAC network adapter
@@ -1484,8 +1489,14 @@ static int emac_dev_open(struct net_device *ndev)
 
 	/* use the first phy on the bus if pdata did not give us a phy id */
 	if (!phydev && !priv->phy_id) {
-		phy = bus_find_device_by_name(&mdio_bus_type, NULL,
-					      "davinci_mdio");
+		/* NOTE: we can't use bus_find_device_by_name() here because
+		 * the device name is not guaranteed to be 'davinci_mdio'. On
+		 * some systems it can be 'davinci_mdio.0' so we need to use
+		 * strncmp() against the first part of the string to correctly
+		 * match it.
+		 */
+		phy = bus_find_device(&mdio_bus_type, NULL, NULL,
+				      match_first_device);
 		if (phy) {
 			priv->phy_id = dev_name(phy);
 			if (!priv->phy_id || !*priv->phy_id)
-- 
2.17.1

[PATCH 2/3] net: phy: set the of_node in the mdiodev's struct device

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Copy the of_node over from mii_bus's struct device. This is needed
for device-tree systems to be able to check the mdio device's
compatible string.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/net/phy/phy_device.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index bd0f339f69fd..a92d5ee61813 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -411,6 +411,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
 	mdiodev->dev.parent = &bus->dev;
 	mdiodev->dev.bus = &mdio_bus_type;
 	mdiodev->dev.type = &mdio_bus_phy_type;
+	mdiodev->dev.of_node = bus->dev.of_node;
 	mdiodev->bus = bus;
 	mdiodev->bus_match = phy_bus_match;
 	mdiodev->addr = addr;
-- 
2.17.1

[PATCH 3/3] net: davinci_emac: match the mdio device against its compatible if possible

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Device tree based systems without of_dev_auxdata will have the mdio
device named differently than "davinci_mdio(.0)". In this case use the
device's compatible string for matching.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/net/ethernet/ti/davinci_emac.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index a1a6445b5a7e..c28a35bb852f 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1387,6 +1387,10 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
 
 static int match_first_device(struct device *dev, void *data)
 {
+	if (dev->of_node)
+		return of_device_is_compatible(dev->of_node,
+					       "ti,davinci_mdio");
+
 	return !strncmp(dev_name(dev), "davinci_mdio", 12);
 }
 
-- 
2.17.1

Re: [PATCH 1/3] net: ethernet: fix suspend/resume in davinci_emac

[Florian Fainelli]

On 06/19/2018 09:09 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> This patch reverts commit 3243ff2a05ec ("net: ethernet: davinci_emac:
> Deduplicate bus_find_device() by name matching") and adds a comment
> which should stop anyone from reintroducing the same "fix" in the future.
> 
> We can't use bus_find_device_by_name() here because the device name is
> not guaranteed to be 'davinci_mdio'. On some systems it can be
> 'davinci_mdio.0' so we need to use strncmp() against the first part of
> the string to correctly match it.
> 
> Fixes: 3243ff2a05ec ("net: ethernet: davinci_emac: Deduplicate bus_find_device() by name matching")
> Cc: stable@vger.kernel.org
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/net/ethernet/ti/davinci_emac.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index 06d7c9e4dcda..a1a6445b5a7e 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -1385,6 +1385,11 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
>  		return -EOPNOTSUPP;
>  }
>  
> +static int match_first_device(struct device *dev, void *data)
> +{
> +	return !strncmp(dev_name(dev), "davinci_mdio", 12);

	const char *bus_name = "davinci_mdio";

	return !strncmp(dev_name(dev), bus_name, strlen(bus_name));

Or even better yet, if you want to make sure this really is a PHY device
that you are trying to match, you could try to use sscanf() with PHY_ID_FMT.
-- 
Florian

Re: [PATCH 2/3] net: phy: set the of_node in the mdiodev's struct device

[Florian Fainelli]

On 06/19/2018 09:09 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Copy the of_node over from mii_bus's struct device. This is needed
> for device-tree systems to be able to check the mdio device's
> compatible string.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/net/phy/phy_device.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index bd0f339f69fd..a92d5ee61813 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -411,6 +411,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
>  	mdiodev->dev.parent = &bus->dev;
>  	mdiodev->dev.bus = &mdio_bus_type;
>  	mdiodev->dev.type = &mdio_bus_phy_type;
> +	mdiodev->dev.of_node = bus->dev.of_node;

That does not quite make sense to me, the mdio device's parent already
points to &bus->dev, which would get you the correct of_node. You are
breaking the parent/child relationship here. From patch 3, see my
comments there, it does not look like you are matching on the right
device level.

>  	mdiodev->bus = bus;
>  	mdiodev->bus_match = phy_bus_match;
>  	mdiodev->addr = addr;
> 


-- 
Florian

Re: [PATCH 3/3] net: davinci_emac: match the mdio device against its compatible if possible

[Florian Fainelli]

On 06/19/2018 09:09 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Device tree based systems without of_dev_auxdata will have the mdio
> device named differently than "davinci_mdio(.0)". In this case use the
> device's compatible string for matching.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/net/ethernet/ti/davinci_emac.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index a1a6445b5a7e..c28a35bb852f 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -1387,6 +1387,10 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
>  
>  static int match_first_device(struct device *dev, void *data)
>  {
> +	if (dev->of_node)
> +		return of_device_is_compatible(dev->of_node,
> +					       "ti,davinci_mdio");

Why would we be matching the PHY device with the MDIO controller
compatibe string? Why not check dev->parent.of_node instead which would
make more sense?
-- 
Florian

Re: [PATCH 1/3] net: ethernet: fix suspend/resume in davinci_emac

[Lukas Wunner]

On Tue, Jun 19, 2018 at 06:09:48PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> This patch reverts commit 3243ff2a05ec ("net: ethernet: davinci_emac:
> Deduplicate bus_find_device() by name matching") and adds a comment
> which should stop anyone from reintroducing the same "fix" in the future.
> 
> We can't use bus_find_device_by_name() here because the device name is
> not guaranteed to be 'davinci_mdio'. On some systems it can be
> 'davinci_mdio.0' so we need to use strncmp() against the first part of
> the string to correctly match it.
> 
> Fixes: 3243ff2a05ec ("net: ethernet: davinci_emac: Deduplicate bus_find_device() by name matching")
> Cc: stable@vger.kernel.org
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This is still

Acked-by: Lukas Wunner <lukas@wunner.de>

given that my patch which is reverted here seems to have been incorrect.
Feel free to keep the ack if you respin in response to Florian Fainelli's
comments.

Thanks,

Lukas

> ---
>  drivers/net/ethernet/ti/davinci_emac.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index 06d7c9e4dcda..a1a6445b5a7e 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -1385,6 +1385,11 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
>  		return -EOPNOTSUPP;
>  }
>  
> +static int match_first_device(struct device *dev, void *data)
> +{
> +	return !strncmp(dev_name(dev), "davinci_mdio", 12);
> +}
> +
>  /**
>   * emac_dev_open - EMAC device open
>   * @ndev: The DaVinci EMAC network adapter
> @@ -1484,8 +1489,14 @@ static int emac_dev_open(struct net_device *ndev)
>  
>  	/* use the first phy on the bus if pdata did not give us a phy id */
>  	if (!phydev && !priv->phy_id) {
> -		phy = bus_find_device_by_name(&mdio_bus_type, NULL,
> -					      "davinci_mdio");
> +		/* NOTE: we can't use bus_find_device_by_name() here because
> +		 * the device name is not guaranteed to be 'davinci_mdio'. On
> +		 * some systems it can be 'davinci_mdio.0' so we need to use
> +		 * strncmp() against the first part of the string to correctly
> +		 * match it.
> +		 */
> +		phy = bus_find_device(&mdio_bus_type, NULL, NULL,
> +				      match_first_device);
>  		if (phy) {
>  			priv->phy_id = dev_name(phy);
>  			if (!priv->phy_id || !*priv->phy_id)
> -- 
> 2.17.1
> 

Re: [PATCH 1/3] net: ethernet: fix suspend/resume in davinci_emac

[Bartosz Golaszewski]

2018-06-19 18:55 GMT+02:00 Florian Fainelli <f.fainelli@gmail.com>:
> On 06/19/2018 09:09 AM, Bartosz Golaszewski wrote:
>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>
>> This patch reverts commit 3243ff2a05ec ("net: ethernet: davinci_emac:
>> Deduplicate bus_find_device() by name matching") and adds a comment
>> which should stop anyone from reintroducing the same "fix" in the future.
>>
>> We can't use bus_find_device_by_name() here because the device name is
>> not guaranteed to be 'davinci_mdio'. On some systems it can be
>> 'davinci_mdio.0' so we need to use strncmp() against the first part of
>> the string to correctly match it.
>>
>> Fixes: 3243ff2a05ec ("net: ethernet: davinci_emac: Deduplicate bus_find_device() by name matching")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  drivers/net/ethernet/ti/davinci_emac.c | 15 +++++++++++++--
>>  1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
>> index 06d7c9e4dcda..a1a6445b5a7e 100644
>> --- a/drivers/net/ethernet/ti/davinci_emac.c
>> +++ b/drivers/net/ethernet/ti/davinci_emac.c
>> @@ -1385,6 +1385,11 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
>>               return -EOPNOTSUPP;
>>  }
>>
>> +static int match_first_device(struct device *dev, void *data)
>> +{
>> +     return !strncmp(dev_name(dev), "davinci_mdio", 12);
>
>         const char *bus_name = "davinci_mdio";
>
>         return !strncmp(dev_name(dev), bus_name, strlen(bus_name));
>
> Or even better yet, if you want to make sure this really is a PHY device
> that you are trying to match, you could try to use sscanf() with PHY_ID_FMT.
> --
> Florian

I don't think this is necessary. This simple function would get too
complicated with the additional buffer for the sscanf'ed phy name etc.

Thanks,
Bart