Message ID | 1418302951-9309-4-git-send-email-octavian.purdila@intel.com |
---|---|
State | Not Applicable |
Headers | show |
On Thu, Dec 11, 2014 at 03:02:31PM +0200, Octavian Purdila wrote: > Without suspend/resume functionality in the USB driver the USB core > will disconnect and reconnect the DLN2 port and because the GPIO > framework does not yet support removal of an in-use controller a > suspend/resume operation will result in a crash. > > This patch provides suspend and resume functions for the DLN2 driver > so that the above scenario is avoided. > > Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> > --- > drivers/mfd/dln2.c | 41 ++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 38 insertions(+), 3 deletions(-) > > diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c > index 6d49685..08c403c 100644 > --- a/drivers/mfd/dln2.c > +++ b/drivers/mfd/dln2.c > @@ -587,7 +587,6 @@ static void dln2_free_rx_urbs(struct dln2_dev *dln2) > int i; > > for (i = 0; i < DLN2_MAX_URBS; i++) { > - usb_kill_urb(dln2->rx_urb[i]); > usb_free_urb(dln2->rx_urb[i]); > kfree(dln2->rx_buf[i]); > } Now dln2_free will no longer stop the urbs before releasing them and hence you can get a use after free in the error path of probe where dln2_free is called after you have submitted the urbs. Please be more careful. Splitting allocation and submission (and reuse that helper in resume) and adding a stop_rx_urbs helper might be a good idea. > @@ -665,9 +664,8 @@ static const struct mfd_cell dln2_devs[] = { > }, > }; > > -static void dln2_disconnect(struct usb_interface *interface) > +static void dln2_stop(struct dln2_dev *dln2) > { > - struct dln2_dev *dln2 = usb_get_intfdata(interface); > int i, j; > > /* don't allow starting new transfers */ > @@ -696,6 +694,16 @@ static void dln2_disconnect(struct usb_interface *interface) > /* wait for transfers to end */ > wait_event(dln2->disconnect_wq, !dln2->active_transfers); > > + for (i = 0; i < DLN2_MAX_URBS; i++) > + usb_kill_urb(dln2->rx_urb[i]); > +} > + > +static void dln2_disconnect(struct usb_interface *interface) > +{ > + struct dln2_dev *dln2 = usb_get_intfdata(interface); > + > + dln2_stop(dln2); > + > mfd_remove_devices(&interface->dev); > > dln2_free(dln2); > @@ -767,11 +775,38 @@ static const struct usb_device_id dln2_table[] = { > > MODULE_DEVICE_TABLE(usb, dln2_table); I believe I already asked you to place the new callbacks above the id table. > +static int dln2_suspend(struct usb_interface *iface, pm_message_t message) > +{ > + struct dln2_dev *dln2 = usb_get_intfdata(iface); > + > + dln2_stop(dln2); > + return 0; > +} > + > +static int dln2_resume(struct usb_interface *iface) > +{ > + struct dln2_dev *dln2 = usb_get_intfdata(iface); > + int i; > + int ret = 0; > + > + dln2->disconnect = false; > + > + for (i = 0; i < DLN2_MAX_URBS; i++) { > + ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL); You cannot use GFP_KERNEL in resume, use GFP_NOIO. > + if (ret) Add a dev_err here. > + break; > + } > + > + return ret; > +} Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c index 6d49685..08c403c 100644 --- a/drivers/mfd/dln2.c +++ b/drivers/mfd/dln2.c @@ -587,7 +587,6 @@ static void dln2_free_rx_urbs(struct dln2_dev *dln2) int i; for (i = 0; i < DLN2_MAX_URBS; i++) { - usb_kill_urb(dln2->rx_urb[i]); usb_free_urb(dln2->rx_urb[i]); kfree(dln2->rx_buf[i]); } @@ -665,9 +664,8 @@ static const struct mfd_cell dln2_devs[] = { }, }; -static void dln2_disconnect(struct usb_interface *interface) +static void dln2_stop(struct dln2_dev *dln2) { - struct dln2_dev *dln2 = usb_get_intfdata(interface); int i, j; /* don't allow starting new transfers */ @@ -696,6 +694,16 @@ static void dln2_disconnect(struct usb_interface *interface) /* wait for transfers to end */ wait_event(dln2->disconnect_wq, !dln2->active_transfers); + for (i = 0; i < DLN2_MAX_URBS; i++) + usb_kill_urb(dln2->rx_urb[i]); +} + +static void dln2_disconnect(struct usb_interface *interface) +{ + struct dln2_dev *dln2 = usb_get_intfdata(interface); + + dln2_stop(dln2); + mfd_remove_devices(&interface->dev); dln2_free(dln2); @@ -767,11 +775,38 @@ static const struct usb_device_id dln2_table[] = { MODULE_DEVICE_TABLE(usb, dln2_table); +static int dln2_suspend(struct usb_interface *iface, pm_message_t message) +{ + struct dln2_dev *dln2 = usb_get_intfdata(iface); + + dln2_stop(dln2); + return 0; +} + +static int dln2_resume(struct usb_interface *iface) +{ + struct dln2_dev *dln2 = usb_get_intfdata(iface); + int i; + int ret = 0; + + dln2->disconnect = false; + + for (i = 0; i < DLN2_MAX_URBS; i++) { + ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL); + if (ret) + break; + } + + return ret; +} + static struct usb_driver dln2_driver = { .name = "dln2", .probe = dln2_probe, .disconnect = dln2_disconnect, .id_table = dln2_table, + .suspend = dln2_suspend, + .resume = dln2_resume, }; module_usb_driver(dln2_driver);
Without suspend/resume functionality in the USB driver the USB core will disconnect and reconnect the DLN2 port and because the GPIO framework does not yet support removal of an in-use controller a suspend/resume operation will result in a crash. This patch provides suspend and resume functions for the DLN2 driver so that the above scenario is avoided. Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> --- drivers/mfd/dln2.c | 41 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 3 deletions(-)