From: rogerq@ti•com (Roger Quadros)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/9] usb: otg: use try_module_get in all usb_get_phy functions and add missing module_put
Date: Mon, 4 Feb 2013 16:39:17 +0200 [thread overview]
Message-ID: <510FC815.5030508@ti.com> (raw)
In-Reply-To: <510FC171.3090708@pengutronix.de>
On 02/04/2013 04:10 PM, Marc Kleine-Budde wrote:
> 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@pengutronix•de>
>>>
>>> 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@pengutronix•de>
>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix•de>
>>> ---
>>> 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.
>
Yes, you are right.
cheers,
-roger
next prev parent reply other threads:[~2013-02-04 14:39 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-04 13:24 [PATCH v4] USB: add devicetree helpers for determining dr_mode and phy_type Sascha Hauer
2013-02-04 13:24 ` [PATCH 1/9] usb: otg: use try_module_get in all usb_get_phy functions and add missing module_put Sascha Hauer
2013-02-04 13:59 ` Roger Quadros
2013-02-04 14:10 ` Marc Kleine-Budde
2013-02-04 14:39 ` Roger Quadros [this message]
2013-02-04 13:24 ` [PATCH 2/9] USB: move bulk of otg/otg.c to phy/phy.c Sascha Hauer
2013-02-19 9:30 ` Felipe Balbi
2013-02-19 19:06 ` Sascha Hauer
2013-02-19 19:48 ` Felipe Balbi
2013-02-04 13:24 ` [PATCH 3/9] USB: add devicetree helpers for determining dr_mode and phy_type Sascha Hauer
2013-02-14 9:36 ` Alexander Shishkin
2013-02-14 9:49 ` Marc Kleine-Budde
2013-02-14 9:58 ` Felipe Balbi
2013-02-14 10:07 ` Sascha Hauer
2013-02-14 10:15 ` Felipe Balbi
2013-02-14 11:24 ` Sascha Hauer
2013-02-14 13:10 ` Felipe Balbi
2013-02-14 16:06 ` Sascha Hauer
2013-02-14 18:04 ` Felipe Balbi
2013-02-14 18:30 ` Sascha Hauer
2013-02-14 19:36 ` Felipe Balbi
2013-02-15 10:54 ` Sascha Hauer
2013-02-17 9:00 ` Peter Chen
2013-02-14 10:11 ` Marc Kleine-Budde
2013-02-14 10:16 ` Felipe Balbi
2013-03-13 9:43 ` Peter Chen
2013-02-04 13:24 ` [PATCH 4/9] USB: chipidea: ci13xxx-imx: create dynamic platformdata Sascha Hauer
2013-02-04 13:24 ` [PATCH 5/9] USB: chipidea: add PTW and PTS handling Sascha Hauer
2013-02-14 13:07 ` Alexander Shishkin
2013-02-27 10:23 ` Marc Kleine-Budde
2013-02-04 13:24 ` [PATCH 6/9] USB chipidea: introduce dual role mode pdata flags Sascha Hauer
2013-02-22 2:09 ` Peter Chen
2013-02-27 10:42 ` Marc Kleine-Budde
2013-02-04 13:24 ` [PATCH 7/9] USB chipidea i.MX: introduce dr_mode property Sascha Hauer
2013-02-04 13:24 ` [PATCH 8/9] USB mxs-phy: Register phy with framework Sascha Hauer
2013-02-04 13:24 ` [PATCH 9/9] USB chipidea i.MX: use devm_usb_get_phy_by_phandle to get phy Sascha Hauer
2013-02-05 11:45 ` Sergei Shtylyov
2013-02-05 11:58 ` Sascha Hauer
2013-02-05 5:54 ` [PATCH v4] USB: add devicetree helpers for determining dr_mode and phy_type Peter Chen
2013-02-07 10:56 ` Sascha Hauer
2013-02-12 13:59 ` Sascha Hauer
2013-02-14 13:22 ` Alexander Shishkin
-- strict thread matches above, loose matches on Subject: below --
2013-02-27 12:27 [PATCH v5 0/9] " Marc Kleine-Budde
2013-02-27 12:27 ` [PATCH 1/9] USB otg: use try_module_get in all usb_get_phy functions and add missing module_put Marc Kleine-Budde
2013-02-27 12:31 ` Felipe Balbi
2013-02-27 12:40 ` Marc Kleine-Budde
2013-02-27 12:43 ` Felipe Balbi
2013-02-27 12:46 ` Marc Kleine-Budde
2013-02-27 12:47 ` Felipe Balbi
2013-02-27 12:55 ` Marc Kleine-Budde
2013-02-27 13:42 ` Felipe Balbi
2013-02-27 13:55 ` Marc Kleine-Budde
2013-02-27 14:21 ` Marc Kleine-Budde
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