From: Nestor Lopez Casado <nlopezcasad@xxxxxxxxxxxx> On big-endian systems (e.g., Apple PowerBook), trying to use a logitech wireless mouse with the Logitech Unifying Receiver does not work with v3.2 and later kernels. The device doesn't show up in /dev/input. Older kernels work fine. That is because the new hid-logitech-dj driver claims the device. The device arrival notification appears: 20 00 41 02 00 00 00 00 00 00 00 00 00 00 00 and we read the report_types bitfield (02 00 00 00) to find out what kind of device it is. Unfortunately the driver only reads the first 8 bits and treats that value as a 32-bit little-endian number, so on a powerpc the report type seems to be 0x02000000 and is not recognized. Even on little-endian machines, connecting a media center remote control (report type 00 01 00 00) with this driver loaded would presumably fail for the same reason. Fix both problems by using get_unaligned_le32() to read all four bytes, which is a little clearer anyway. After this change, the wireless mouse works on Hugo's PowerBook again. Addresses http://bugs.debian.org/671292 [jn: with commit message and tweaked to use get_unaligned instead of copying onto the stack] Reported-by: Hugo Osvaldo Barrera <hugo@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> --- Change since v1: fixed attribution. I had been wondering why the patch you sent before didn't fix Hugo's problem while the effectively identical patch I sent did. The only explanation I can think of is an error introduced in applying the patch by hand. drivers/hid/hid-logitech-dj.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c index 38b12e45780c..2eac8c566b17 100644 --- a/drivers/hid/hid-logitech-dj.c +++ b/drivers/hid/hid-logitech-dj.c @@ -26,6 +26,7 @@ #include <linux/hid.h> #include <linux/module.h> #include <linux/usb.h> +#include <asm/unaligned.h> #include "usbhid/usbhid.h" #include "hid-ids.h" #include "hid-logitech-dj.h" @@ -265,8 +266,8 @@ static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev, goto dj_device_allocate_fail; } - dj_dev->reports_supported = le32_to_cpu( - dj_report->report_params[DEVICE_PAIRED_RF_REPORT_TYPE]); + dj_dev->reports_supported = get_unaligned_le32( + dj_report->report_params + DEVICE_PAIRED_RF_REPORT_TYPE); dj_dev->hdev = dj_hiddev; dj_dev->dj_receiver_dev = djrcv_dev; dj_dev->device_index = dj_report->device_index; -- 1.7.10.1 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
