Fix for Chromecast Remote not working

Fix for Chromecast Remote not working

[Randy Sommerfeld]

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Hello,

I've attached source code for a kernel module that fixes my Chromecast 
Remote.  Prior to this module, when pressing buttons on the Chromecast 
Remote, I'd get these in the dmesg:

hid-generic 0005:18D1:9450.0004: Event data for report 1 was too short 
(2 vs 1)

It seemed like a simple fix (accepting 1 instead of 2 for this specific 
remote), and the attached module fixes this.

I'm not sure where this belongs in the main tree (perhaps as a quirk in 
drivers/hid/ somewhere), which is why I'm submitting this as a module 
instead of a patch.

As an unsophisticated dev I thought I'd bring this to someone's 
attention since it might allow these remotes to be useful, and the fix 
seems simple.  Thank you.

Cheers,
-Randy.

[-- Attachment #2: chromecast_remote.c --]
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#include <linux/hid.h>
#include <linux/module.h>

#define USB_VENDOR_ID_GOOGLE 0x18d1
#define USB_DEVICE_ID_CHROMECAST_REMOTE 0x9450

static const __u8 *cc_remote_report_fixup(struct hid_device *hdev,
                                    __u8 *rdesc,
                                    unsigned int *rsize)
{
        if (*rsize == 0x39 &&
            rdesc[0x32] == 0x95 &&
            rdesc[0x33] == 0x02 &&
            rdesc[0x34] == 0x75 &&
            rdesc[0x35] == 0x08) {
                hid_info(hdev, "fixing Chromecast Remote descriptor\n");
                rdesc[0x33] = 0x01;
        }

        return rdesc;
}

static const struct hid_device_id cc_remote_devices[] = {
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE,
                               USB_DEVICE_ID_CHROMECAST_REMOTE) },
        { }
};
MODULE_DEVICE_TABLE(hid, cc_remote_devices);

static struct hid_driver cc_remote_driver = {
        .name = "chromecast_remote",
        .id_table = cc_remote_devices,
        .report_fixup = cc_remote_report_fixup,
};

module_hid_driver(cc_remote_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Chromecast Remote HID descriptor fixup");