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authorKevin Daughtridge <kevin@kdau.com>2012-09-20 12:00:32 -0700
committerJiri Kosina <jkosina@suse.cz>2012-10-01 10:09:26 +0200
commit86e6b77eb7cf9ca2e9c7092b4dfd588f0a3307b6 (patch)
treed00ef9d1f11bae93c5e809246f8eae156d74b1ed /drivers
parent4cc9834518efed3b69d3a8ff3bd162e089f68d34 (diff)
downloadlinux-86e6b77eb7cf9ca2e9c7092b4dfd588f0a3307b6.tar.gz
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hid/hid-core.c16
-rw-r--r--drivers/hid/usbhid/hid-core.c6
2 files changed, 16 insertions, 6 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index dd679a582c2..ec917690c26 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 dedd8e4e5c6..8e0c4bf94eb 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");