HID: fixup quirk for NCR devices (5b915d9e) · Commits · 戴 / test

NCR devices are terminally broken by design -- they claim themselves to contain proper input applications in their HID report descriptor, but behave very badly if treated in standard way. According to NCR developers, the devices get confused when queried for reports in a standard way, rendering them unusable. NCR is shipping application called "RPSL" that can be used to drive these devices through hiddev, under the assumption that in-kernel driver doesn't perform initial report query. If it does, neither in-kernel nor hiddev-based driver can operate with these devices any more. Introduce a quirk that skips the report query for all NCR devices. The previous NOGET quirk was wrong and had been introduced because I misunderstood the nature of brokenness of these devices. Signed-off-by:

Jiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hid-core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -996,6 +996,7 @@ static int usbhid_start(struct hid_device *hid)
		usbhid->urbctrl->transfer_dma = usbhid->ctrlbuf_dma;
		usbhid->urbctrl->transfer_flags \|= (URB_NO_TRANSFER_DMA_MAP \| URB_NO_SETUP_DMA_MAP);

		if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
		usbhid_init_reports(hid);

		set_bit(HID_STARTED, &usbhid->iofl);

drivers/hid/usbhid/hid-quirks.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -281,7 +281,7 @@ u32 usbhid_lookup_quirk(const u16 idVendor, const u16 idProduct)
		if (idVendor == USB_VENDOR_ID_NCR &&
		idProduct >= USB_DEVICE_ID_NCR_FIRST &&
		idProduct <= USB_DEVICE_ID_NCR_LAST)
		return HID_QUIRK_NOGET;
		return HID_QUIRK_NO_INIT_REPORTS;

		down_read(&dquirks_rwsem);
		bl_entry = usbhid_exists_dquirk(idVendor, idProduct);

include/linux/hid.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -312,6 +312,7 @@ struct hid_item {
		#define HID_QUIRK_MULTI_INPUT 0x00000040
		#define HID_QUIRK_SKIP_OUTPUT_REPORTS 0x00010000
		#define HID_QUIRK_FULLSPEED_INTERVAL 0x10000000
		#define HID_QUIRK_NO_INIT_REPORTS 0x20000000

		/*
		* This is the global environment of the parser. This information is

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