From 44d27f7dfedd9aadc082cda31462f6600f56e4ec Mon Sep 17 00:00:00 2001 From: Jonathan Nieder Date: Fri, 11 May 2012 16:17:16 +0200 Subject: [PATCH] HID: logitech: read all 32 bits of report type bitfield 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. Based on a patch by Nestor Lopez Casado. Addresses http://bugs.debian.org/671292 Reported-by: Hugo Osvaldo Barrera Inspired-by: Nestor Lopez Casado Signed-off-by: Jonathan Nieder Signed-off-by: Nestor Lopez Casado Cc: Signed-off-by: Jiri Kosina --- 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 2b56efcbdf61..d44ea58c597e 100644 --- a/drivers/hid/hid-logitech-dj.c +++ b/drivers/hid/hid-logitech-dj.c @@ -26,6 +26,7 @@ #include #include #include +#include #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; -- 2.30.2