[PATCH net v2 2/3] drivers: net: cpsw: fix error messages when using phy-handle DT property
Grygorii Strashko
grygorii.strashko at ti.com
Mon Apr 25 12:12:20 PDT 2016
On 04/22/2016 06:45 PM, David Rivshin (Allworx) wrote:
> On Fri, 22 Apr 2016 16:03:34 +0300
> Grygorii Strashko <grygorii.strashko at ti.com> wrote:
>
>> On 04/21/2016 09:26 PM, David Rivshin (Allworx) wrote:
>>> From: David Rivshin <drivshin at allworx.com>
>>>
>>> The phy-handle, phy_id, and fixed-link properties are mutually exclusive,
>>> and only one need be specified. However if phy-handle was specified, an
>>> error message would complain about the lack of phy_id or fixed-link.
I think, commit message need to be updated.
You not only fix log messages - you also fix the issue with
of_get_phy_mode(slave_node); which will not be called if phy-handle is used.
slave_data->phy_if = of_get_phy_mode(slave_node);
^ see below
>>>
>>> Also, if phy-handle was specified and the subsequent of_phy_connect()
>>> failed, the error message still referenced slaved->data->phy_id, which
>>> would be empty. Instead, use the name of the device_node as a useful
>>> identifier.
>>>
>>> Fixes: 9e42f715264f ("drivers: net: cpsw: add phy-handle parsing")
>>> Signed-off-by: David Rivshin <drivshin at allworx.com>
>>> Acked-by: Rob Herring <robh at kernel.org>
>>> Tested-by: Nicolas Chauvet <kwizart at gmail.com>
>>> ---
>>> If would like this for -stable it should apply cleanly as far back
>>> as 4.5. It failes on 4.4 due to some context differences, but can be
>>> applied with 'git am -C2'. Or, I can produce a separate patch against
>>> linux-4.4.y if preferred.
>>>
>>> Changes since v1 [1]:
>>> - Rebased (no conflicts)
>>> - Added Tested-by from Nicolas Chauvet
>>> - Added Acked-by from Rob Herring for the binding change
>>>
>>> [1] https://patchwork.ozlabs.org/patch/560324/
>>>
>>> Documentation/devicetree/bindings/net/cpsw.txt | 4 ++--
>>> drivers/net/ethernet/ti/cpsw.c | 17 +++++++++++++----
>>> 2 files changed, 15 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/cpsw.txt b/Documentation/devicetree/bindings/net/cpsw.txt
>>> index 28a4781..3033c0f 100644
>>> --- a/Documentation/devicetree/bindings/net/cpsw.txt
>>> +++ b/Documentation/devicetree/bindings/net/cpsw.txt
>>> @@ -46,16 +46,16 @@ Optional properties:
>>> - dual_emac_res_vlan : Specifies VID to be used to segregate the ports
>>> - mac-address : See ethernet.txt file in the same directory
>>> - phy_id : Specifies slave phy id
>>
>> May be the "phy_id" can be marked as deprecated? (while here)
>> The recommended property now is "phy-handle".
>
> I can certainly do that. Perhaps something like this?
> - phy_id : Specifies slave phy id (deprecated, use phy-handle)
>
> Rob, would you have any issues with bundling that?
>
>>
>>> - phy-handle : See ethernet.txt file in the same directory
>>>
>>> Slave sub-nodes:
>>> - fixed-link : See fixed-link.txt file in the same directory
>>> - Either the property phy_id, or the sub-node
>>> - fixed-link can be specified
>>> +
>>> +Note: Exactly one of phy_id, phy-handle, or fixed-link must be specified.
>>>
>>> Note: "ti,hwmods" field is used to fetch the base address and irq
>>> resources from TI, omap hwmod data base during device registration.
>>> Future plan is to migrate hwmod data base contents into device tree
>>> blob so that, all the required data will be used from device tree dts
>>> file.
>>>
>>> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
>>> index d69cb3f..3c81413 100644
>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>> @@ -1150,16 +1150,19 @@ static void cpsw_slave_open(struct cpsw_slave *slave, struct cpsw_priv *priv)
>>> if (slave->data->phy_node)
>>> slave->phy = of_phy_connect(priv->ndev, slave->data->phy_node,
>>> &cpsw_adjust_link, 0, slave->data->phy_if);
>>> else
>>> slave->phy = phy_connect(priv->ndev, slave->data->phy_id,
>>> &cpsw_adjust_link, slave->data->phy_if);
>>> if (IS_ERR(slave->phy)) {
>>> - dev_err(priv->dev, "phy %s not found on slave %d\n",
>>> - slave->data->phy_id, slave->slave_num);
>>> + dev_err(priv->dev, "phy \"%s\" not found on slave %d\n",
>>> + slave->data->phy_node ?
>>> + slave->data->phy_node->full_name :
>>> + slave->data->phy_id,
>>> + slave->slave_num);
>>
>> Unfortunately, there are some inconsistency between legacy and FDT API :(
>> of_phy_connect() will return valid phy_device or NULL, but phy_connect()
>> can return valid phy_device or ERR_PTR().
>
> Good catch, I hadn't noticed that. It looks like that's actually a more
> serious (pre-existing) bug: if of_phy_connect() returns NULL, we'd end
> up dereferencing it and pagefaulting.
>
> How about moving the IS_ERR() check into the phy_connect() case like this:
> if (slave->data->phy_node) {
> slave->phy = of_phy_connect(priv->ndev, slave->data->phy_node,
> &cpsw_adjust_link, 0, slave->data->phy_if);
[1]
> } else {
> slave->phy = phy_connect(priv->ndev, slave->data->phy_id,
> &cpsw_adjust_link, slave->data->phy_if);
> if (IS_ERR(slave->phy))
> slave->phy = NULL;
[2]
> }
> if (!slave->phy) {
> dev_err(priv->dev, "phy \"%s\" not found on slave %d\n",
> slave->data->phy_node ?
> slave->data->phy_node->full_name :
> slave->data->phy_id,
> slave->slave_num);
> } else {
>
> Since you say the phy_id case is deprecated anyways, I'm not too concerned
> about not printing the error code returned by phy_connect() in that case
> (especially since it never did so in the past). That lets us still avoid
> duplicating the dev_err() itself.
I'm not worry too much about duplicating dev_err() - it's always good to know
the reason of failure.
So, may be for of_phy_connect() [1]:
dev_err(priv->dev, "phy \"%s\" not found on slave %d\n",
slave->data->phy_node->full_name,
slave->slave_num);
and for phy_connect() [2]:
dev_err(priv->dev, "phy %s not found on slave %d, err %d\n",
slave->data->phy_id, slave->slave_num, PTR_ERR(slave->phy));
Mugunthan, any comments?
>
>
>>
>>
>>
>>> slave->phy = NULL;
>>> } else {
>>> phy_attached_info(slave->phy);
>>>
>>> phy_start(slave->phy);
>>>
>>> /* Configure GMII_SEL register */
>>> @@ -2030,15 +2033,19 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
>>> /* This is no slave child node, continue */
>>> if (strcmp(slave_node->name, "slave"))
>>> continue;
>>>
>>> slave_data->phy_node = of_parse_phandle(slave_node,
>>> "phy-handle", 0);
>>> parp = of_get_property(slave_node, "phy_id", &lenp);
>>> - if (of_phy_is_fixed_link(slave_node)) {
>>> + if (slave_data->phy_node) {
>>> + dev_dbg(&pdev->dev,
>>> + "slave[%d] using phy-handle=\"%s\"\n",
>>> + i, slave_data->phy_node->full_name);
>>> + } else if (of_phy_is_fixed_link(slave_node)) {
>>> struct device_node *phy_node;
>>> struct phy_device *phy_dev;
>>>
>>> /* In the case of a fixed PHY, the DT node associated
>>> * to the PHY is the Ethernet MAC DT node.
>>> */
>>> ret = of_phy_register_fixed_link(slave_node);
>>> @@ -2067,15 +2074,17 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
>>> if (!mdio) {
>>> dev_err(&pdev->dev, "Missing mdio platform device\n");
>>> return -EINVAL;
>>> }
>>> snprintf(slave_data->phy_id, sizeof(slave_data->phy_id),
>>> PHY_ID_FMT, mdio->name, phyid);
>>> } else {
>>> - dev_err(&pdev->dev, "No slave[%d] phy_id or fixed-link property\n", i);
>>> + dev_err(&pdev->dev,
>>> + "No slave[%d] phy_id, phy-handle, or fixed-link property\n",
>>> + i);
>>> goto no_phy_slave;
>>> }
>>> slave_data->phy_if = of_get_phy_mode(slave_node);
Your change will allow the code to reach this point in case of phy-handle.
>>> if (slave_data->phy_if < 0) {
>>> dev_err(&pdev->dev, "Missing or malformed slave[%d] phy-mode property\n",
>>> i);
>>> return slave_data->phy_if;
>>>
>>
>>
--
regards,
-grygorii
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