linux.git/drivers/usb/core/hcd.c, branch v2.6.38

USB: fix race between root-hub resume and wakeup requests

2011-02-04T00:46:48+00:00

The USB core keeps track of pending resume requests for root hubs, in
order to resolve races between wakeup requests and suspends.  However
the code that does this is subject to another race (between wakeup
requests and resumes) because the WAKEUP_PENDING flag is cleared
before the resume occurs, leaving a window in which another wakeup
request might arrive.

This patch (as1447) fixes the problem by clearing the WAKEUP_PENDING
flag after the resume instead of before it.

This fixes Bugzilla #24952.

Signed-off-by: Alan Stern 
Tested-by: Paul Bender 
Tested-by: warpme 
Cc: stable  [.36+]
Signed-off-by: Greg Kroah-Hartman

Merge branch 'usb-next' into musb-merge

2010-12-16T18:05:06+00:00

* usb-next: (132 commits)
  USB: uas: Use GFP_NOIO instead of GFP_KERNEL in I/O submission path
  USB: uas: Ensure we only bind to a UAS interface
  USB: uas: Rename sense pipe and sense urb to status pipe and status urb
  USB: uas: Use kzalloc instead of kmalloc
  USB: uas: Fix up the Sense IU
  usb: musb: core: kill unneeded #include's
  DA8xx: assign name to MUSB IRQ resource
  usb: gadget: g_ncm added
  usb: gadget: f_ncm.c added
  usb: gadget: u_ether: prepare for NCM
  usb: pch_udc: Fix setup transfers with data out
  usb: pch_udc: Fix compile error, warnings and checkpatch warnings
  usb: add ab8500 usb transceiver driver
  USB: gadget: Implement runtime PM for MSM bus glue driver
  USB: gadget: Implement runtime PM for ci13xxx gadget
  USB: gadget: Add USB controller driver for MSM SoC
  USB: gadget: Introduce ci13xxx_udc_driver struct
  USB: gadget: Initialize ci13xxx gadget device's coherent DMA mask
  USB: gadget: Fix "scheduling while atomic" bugs in ci13xxx_udc
  USB: gadget: Separate out PCI bus code from ci13xxx_udc
  ...

usb: musb: do not use dma for control transfers

2010-11-22T10:55:02+00:00

The Inventra DMA engine used with the MUSB controller in many
SoCs cannot use DMA for control transfers on EP0, but can use
DMA for all other transfers.

The USB core maps urbs for DMA if hcd->self.uses_dma is true.
(hcd->self.uses_dma is true for MUSB as well).

Split the uses_dma flag into two - one that says if the
controller needs to use PIO for control transfers, and
another which says if the controller uses DMA (for all
other transfers).

Also, populate this flag for all MUSB by default.

(Tested on OMAP3 and OMAP4 boards, with EHCI and MUSB HCDs
simultaneously in use).

Signed-off-by: Maulik Mankad 
Signed-off-by: Santosh Shilimkar 
Signed-off-by: Anand Gadiyar 
Cc: Oliver Neukum 
Cc: Alan Stern 
Cc: Praveena NADAHALLY 
Cc: Ajay Kumar Gupta 
Signed-off-by: Felipe Balbi

USB: make usb_mark_last_busy use pm_runtime_mark_last_busy

2010-11-16T22:02:54+00:00

Since the runtime-PM core already defines a .last_busy field in
device.power, this patch uses it to replace the .last_busy field
defined in usb_device and uses pm_runtime_mark_last_busy to implement
usb_mark_last_busy.

Signed-off-by: Ming Lei 
Reviewed-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: introduce unmap_urb_setup_for_dma()

2010-10-22T17:22:03+00:00

Split unmap_urb_for_dma() to allow just the setup buffer
to be unmapped. This allows HCDs to use PIO for the setup
buffer if it is not suitable for DMA.

Signed-off-by: Martin Fuzzey 
Signed-off-by: Greg Kroah-Hartman

usb: musb: host: unmap the buffer for PIO data transfers

2010-10-22T17:21:53+00:00

The USB stack maps the buffer for DMA if the controller supports DMA.
MUSB controller can perform DMA as well as PIO transfers.
The buffer needs to be unmapped before CPU can perform
PIO data transfers.

Export unmap_urb_for_dma() so that drivers can perform
the DMA unmapping in a sane way.

Signed-off-by: Maulik Mankad 
Acked-by: Alan Stern 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman

USB: xHCI: Supporting MSI/MSI-X

2010-08-10T21:35:40+00:00

Enable MSI/MSI-X supporting in xhci driver.

Provide the mechanism to fall back using MSI and Legacy IRQs
if MSI-X IRQs register failed.

Signed-off-by: Dong Nguyen 
Signed-off-by: Sarah Sharp ,
Signed-off-by: Greg Kroah-Hartman

USB: EHCI: fix NULL pointer dererence in HCDs that use HCD_LOCAL_MEM

2010-08-10T21:35:38+00:00

If we use the HCD_LOCAL_MEM flag and dma_declare_coherent_memory() to
enforce the host controller's local memory utilization we also need to
disable native scatter-gather support, otherwise hcd_alloc_coherent() in
map_urb_for_dma() is called with urb->transfer_buffer == NULL, that
triggers a NULL pointer dereference.

We can also consider to add a WARN_ON() and return an error code to
better catch this problem in the future.

At the moment no driver seems to hit this bug, so I should
consider this a low-priority fix.

Signed-off-by: Andrea Righi 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: fix race between root-hub wakeup & controller suspend

2010-08-10T21:35:38+00:00

This patch (as1395) adds code to hcd_pci_suspend() for handling wakeup
races.  This is another general race pattern, similar to the "open
vs. unregister" race we're all familiar with.  Here, the race is
between suspending a device and receiving a wakeup request from one of
the device's suspended children.

In particular, if a root-hub wakeup is requested at about the same
time as the corresponding USB controller is suspended, and if the
controller is enabled for wakeup, then the controller should either
fail to suspend or else wake right back up again.

During system sleep this won't happen very much, especially since host
controllers generally aren't enabled for wakeup during sleep.  However
it is definitely an issue for runtime PM.  Something like this will be
needed to prevent the controller from autosuspending while waiting for
a root-hub resume to take place.  (That is, in fact, the common case,
for which there is an extra test.)

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: convert usb_hcd bitfields into atomic flags

2010-08-10T21:35:37+00:00

This patch (as1393) converts several of the single-bit fields in
struct usb_hcd to atomic flags.  This is for safety's sake; not all
CPUs can update bitfield values atomically, and these flags are used
in multiple contexts.

The flag fields that are set only during registration or removal can
remain as they are, since non-atomic accesses at those times will not
cause any problems.

(Strictly speaking, the authorized_default flag should become atomic
as well.  I didn't bother with it because it gets changed only via
sysfs.  It can be done later, if anyone wants.)

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman