[PATCH 1/9] usb: otg: use try_module_get in all usb_get_phy functions and add missing module_put
From: Roger Quadros <hidden>
Date: 2013-02-04 13:59:18
On 02/04/2013 03:24 PM, Sascha Hauer wrote:
quoted hunk ↗ jump to hunk
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.
- 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.
I would change the code to
if (IS_ERR(phy)) {
pr_err("unable to find transceiver of type %s\n",
usb_phy_type_string(type));
goto err0;
}
if (!try_module_get(phy->dev->driver->owner)) {
phy = ERR_PTR(-EPROBE_DEFER);
goto err0;
}
quoted hunk ↗ jump to hunk
@@ -228,7 +228,7 @@ struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index) spin_lock_irqsave(&phy_lock, flags); phy = __usb_find_phy_dev(dev, &phy_bind_list, index); - if (IS_ERR(phy)) { + if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) { pr_err("unable to find transceiver\n"); goto err0; }@@ -301,8 +301,12 @@ EXPORT_SYMBOL(devm_usb_put_phy); */ void usb_put_phy(struct usb_phy *x) { - if (x) + if (x) { + struct module *owner = x->dev->driver->owner; + put_device(x->dev); + module_put(owner); + } } EXPORT_SYMBOL(usb_put_phy);
cheers, -roger