[PATCH net v2 2/3] drivers: net: cpsw: fix error messages when using phy-handle DT property
Grygorii Strashko
grygorii.strashko at ti.com
Tue Apr 26 00:50:08 PDT 2016
On 04/26/2016 12:55 AM, David Rivshin (Allworx) wrote:
> On Mon, 25 Apr 2016 22:12:20 +0300
> Grygorii Strashko <grygorii.strashko at ti.com> wrote:
>
>> 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.
>
> You are correct, and that is probably the more important fix compared
> to the error messages.
>
> Because the content is becoming less coherent, what I may do is split
> this patch into 3 small patches:
> A) devicetree binding documentation changes
> B) cpsw_probe_dt changes, with the fixes for of_get_phy_mode() and
> related error message
> C) cpsw_slave_open changes, with the fixes for crash if of_phy_connect
> returns NULL, and related error message
>
> Does that sound reasonable?
Sounds reasonable for me.
Hope patch 1 from this series could be merged separately.
>
>>
>>
>> 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?
>
> If that's the preference, then I can incorporate that into V3.
>
Yes, please, if no other comments.
--
regards,
-grygorii
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