diff options
Diffstat (limited to 'usb.current/usb-allow-drivers-to-use-allocated-bandwidth-until-unbound.patch')
| -rw-r--r-- | usb.current/usb-allow-drivers-to-use-allocated-bandwidth-until-unbound.patch | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/usb.current/usb-allow-drivers-to-use-allocated-bandwidth-until-unbound.patch b/usb.current/usb-allow-drivers-to-use-allocated-bandwidth-until-unbound.patch deleted file mode 100644 index 6930f5143cdf04..00000000000000 --- a/usb.current/usb-allow-drivers-to-use-allocated-bandwidth-until-unbound.patch +++ /dev/null @@ -1,91 +0,0 @@ -From linux-usb-owner@vger.kernel.org Wed Sep 1 13:02:44 2010 -From: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> -To: linux-usb@vger.kernel.org -Cc: linux-kernel@vger.kernel.org, - Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>, - Alan Stern <stern@rowland.harvard.edu>, - Sarah Sharp <sarah.a.sharp@linux.intel.com>, - Greg Kroah-Hartman <gregkh@suse.de> -Subject: usb: allow drivers to use allocated bandwidth until unbound -Date: Sat, 28 Aug 2010 03:06:29 -0300 -Message-Id: <1282975589-22324-1-git-send-email-cascardo@holoscopio.com> - -When using the remove sysfs file, the device configuration is set to -1 -(unconfigured). This eventually unbind drivers with the bandwidth_mutex -held. Some drivers may call functions that hold said mutex, like -usb_reset_device. This is the case for rtl8187, for example. This will -lead to the same process holding the mutex twice, which deadlocks. - -Besides, according to Alan Stern: -"The deadlock problem probably could be handled somehow, but there's a -separate issue: Until the usb_disable_device call finishes unbinding -the drivers, the drivers are free to continue using their allocated -bandwidth. We musn't change the bandwidth allocations until after the -unbinding is done. So this patch is indeed necessary." - -Unbinding the driver before holding the bandwidth_mutex solves the -problem. If any operation after that fails, drivers are not bound again. -But that would be a problem anyway that the user may solve resetting the -device configuration to one that works, just like he would need to do in -most other failure cases. - -Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> -Cc: Alan Stern <stern@rowland.harvard.edu> -Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> -Cc: stable <stable@kernel.org> -Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> - ---- - drivers/usb/core/message.c | 22 +++++++++++----------- - 1 file changed, 11 insertions(+), 11 deletions(-) - ---- a/drivers/usb/core/message.c -+++ b/drivers/usb/core/message.c -@@ -1724,6 +1724,15 @@ free_interfaces: - if (ret) - goto free_interfaces; - -+ /* if it's already configured, clear out old state first. -+ * getting rid of old interfaces means unbinding their drivers. -+ */ -+ if (dev->state != USB_STATE_ADDRESS) -+ usb_disable_device(dev, 1); /* Skip ep0 */ -+ -+ /* Get rid of pending async Set-Config requests for this device */ -+ cancel_async_set_config(dev); -+ - /* Make sure we have bandwidth (and available HCD resources) for this - * configuration. Remove endpoints from the schedule if we're dropping - * this configuration to set configuration 0. After this point, the -@@ -1733,20 +1742,11 @@ free_interfaces: - mutex_lock(&hcd->bandwidth_mutex); - ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL); - if (ret < 0) { -- usb_autosuspend_device(dev); - mutex_unlock(&hcd->bandwidth_mutex); -+ usb_autosuspend_device(dev); - goto free_interfaces; - } - -- /* if it's already configured, clear out old state first. -- * getting rid of old interfaces means unbinding their drivers. -- */ -- if (dev->state != USB_STATE_ADDRESS) -- usb_disable_device(dev, 1); /* Skip ep0 */ -- -- /* Get rid of pending async Set-Config requests for this device */ -- cancel_async_set_config(dev); -- - ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), - USB_REQ_SET_CONFIGURATION, 0, configuration, 0, - NULL, 0, USB_CTRL_SET_TIMEOUT); -@@ -1761,8 +1761,8 @@ free_interfaces: - if (!cp) { - usb_set_device_state(dev, USB_STATE_ADDRESS); - usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); -- usb_autosuspend_device(dev); - mutex_unlock(&hcd->bandwidth_mutex); -+ usb_autosuspend_device(dev); - goto free_interfaces; - } - mutex_unlock(&hcd->bandwidth_mutex); |