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@xxxxxxxx> --- drivers/hid/hid-core.c | 16 +++++++++++++--- drivers/hid/usbhid/hid-core.c | 6 +++--- 2 files changed, 16 insertions(+), 6 deletions(-) Changed in this version: added a temporary buffer to work around report_fixup inconsistencies; using dev_rsize instead of rsize to allocate and read new descriptor. diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 8bcd168..5de3bb3 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 dedd8e4..8e0c4bf94 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"); -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
