diff options
| author | Kevin Daughtridge <kevin@kdau.com> | 2012-09-20 23:00:32 +0400 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2012-10-01 12:09:26 +0400 |
| commit | 86e6b77eb7cf9ca2e9c7092b4dfd588f0a3307b6 (patch) | |
| tree | d00ef9d1f11bae93c5e809246f8eae156d74b1ed | |
| parent | 4cc9834518efed3b69d3a8ff3bd162e089f68d34 (diff) | |
| download | linux-86e6b77eb7cf9ca2e9c7092b4dfd588f0a3307b6.tar.xz | |
HID: keep dev_rdesc unmodified and use it for comparisons
The dev_rdesc member of the hid_device structure is meant to store the original
report descriptor received from the device, but it is currently passed to any
report_fixup method before it is copied to the rdesc member. This patch uses a
temporary buffer to shield dev_rdesc from the side effects of many HID drivers'
report_fixup implementations.
usbhid's hid_post_reset checks the report descriptor currently returned by the
device against a descriptor that may have been modified by a driver's
report_fixup method. That leaves some devices nonfunctional after a resume, with
a "reset_resume error 1" reported. This patch checks the new descriptor against
the unmodified dev_rdesc instead and uses the original, instead of modified,
report size.
BugLink: http://bugs.launchpad.net/bugs/1049623
Signed-off-by: Kevin Daughtridge <kevin@kdau.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | drivers/hid/hid-core.c | 16 | ||||
| -rw-r--r-- | drivers/hid/usbhid/hid-core.c | 6 |
2 files changed, 16 insertions, 6 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index dd679a582c2c..ec917690c263 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -757,6 +757,7 @@ int hid_open_report(struct hid_device *device) struct hid_item item; unsigned int size; __u8 *start; + __u8 *buf; __u8 *end; int ret; static int (*dispatch_type[])(struct hid_parser *parser, @@ -775,12 +776,21 @@ int hid_open_report(struct hid_device *device) return -ENODEV; size = device->dev_rsize; + buf = kmemdup(start, size, GFP_KERNEL); + if (buf == NULL) + return -ENOMEM; + if (device->driver->report_fixup) - start = device->driver->report_fixup(device, start, &size); + start = device->driver->report_fixup(device, buf, &size); + else + start = buf; - device->rdesc = kmemdup(start, size, GFP_KERNEL); - if (device->rdesc == NULL) + start = kmemdup(start, size, GFP_KERNEL); + kfree(buf); + if (start == NULL) return -ENOMEM; + + device->rdesc = start; device->rsize = size; parser = vzalloc(sizeof(struct hid_parser)); diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index dedd8e4e5c6d..8e0c4bf94ebc 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -1415,20 +1415,20 @@ static int hid_post_reset(struct usb_interface *intf) * configuration descriptors passed, we already know that * the size of the HID report descriptor has not changed. */ - rdesc = kmalloc(hid->rsize, GFP_KERNEL); + rdesc = kmalloc(hid->dev_rsize, GFP_KERNEL); if (!rdesc) { dbg_hid("couldn't allocate rdesc memory (post_reset)\n"); return 1; } status = hid_get_class_descriptor(dev, interface->desc.bInterfaceNumber, - HID_DT_REPORT, rdesc, hid->rsize); + HID_DT_REPORT, rdesc, hid->dev_rsize); if (status < 0) { dbg_hid("reading report descriptor failed (post_reset)\n"); kfree(rdesc); return 1; } - status = memcmp(rdesc, hid->rdesc, hid->rsize); + status = memcmp(rdesc, hid->dev_rdesc, hid->dev_rsize); kfree(rdesc); if (status != 0) { dbg_hid("report descriptor changed\n"); |