On 02/04/2013 02:59 PM, Roger Quadros wrote:
> On 02/04/2013 03:24 PM, Sascha Hauer wrote:
>> From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
>>
>> In patch "5d3c28b usb: otg: add device tree support to otg library"
>> devm_usb_get_phy_by_phandle() was added. It uses try_module_get() to lock the
>> phy driver in memory. The corresponding module_put() is missing in that patch.
>>
>> This patch adds try_module_get() to usb_get_phy() and usb_get_phy_dev().
>> Further the missing module_put() is added to usb_put_phy().
>>
>> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
>> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>> ---
>> drivers/usb/otg/otg.c | 10 +++++++---
>> 1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
>> index e181439..2bd03d2 100644
>> --- a/drivers/usb/otg/otg.c
>> +++ b/drivers/usb/otg/otg.c
>> @@ -130,7 +130,7 @@ struct usb_phy *usb_get_phy(enum usb_phy_type type)
>> spin_lock_irqsave(&phy_lock, flags);
>>
>> phy = __usb_find_phy(&phy_list, type);
>> - if (IS_ERR(phy)) {
>> + if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
>> pr_err("unable to find transceiver of type %s\n",
>> usb_phy_type_string(type));
>> goto err0;
>
> There are 2 problems with this.
>
> - If phy was found but try_module_get failed you are not returning error code.
Correct - but....
> - If phy was found and try_module_get fails we would want to use deferred probing,
> since this case is possible if the phy module is not yet loaded and alive but can be in
> the future.
...this should not happen, as the phy list is protected by the
spin_lock. If a phy driver module has added a the phy to the
infrastructure, but has been rmmod'ed without removing the phy. The phy
driver is broken anyway.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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