Re: [PATCH 1/2] input: usb: hid: Bump maximum global item tag report size to 128 bytes
flat view
From: Jiri Kosina <hidden>
Date: 2012-08-15 08:33:26
On Sun, 5 Aug 2012, Marek Vasut wrote:
The Freescale i.MX28 BootROM USB recovery mode implements the USB HID protocol, yet the global item tag report size is 128. Linux checks if this is 96 as of now, see [1]. This causes Linux to refuse to communicate with this device, making it impossible to use the recovery mode. This is not a standard HID device per se, but rather a software emulation implemented within the BootROM code and realized through USB OTG-capable port switched to device mode present on the device. Previous attempt to discuss this issue dates back to 2011, see [2]. There has been not much response. Also noteworthy is the [3], where there seems to be a pointing device that has issue similar to this one. The tool making use of the USB recovery mode is available at [4]. [1] http://comments.gmane.org/gmane.linux.kernel.input/22328 [2] http://www.spinics.net/lists/linux-usb/msg43463.html [3] https://bbs.archlinux.org/viewtopic.php?pid=1141340 [4] http://git.bfuser.eu/?p=marex/mxsldr.git;a=summary Signed-off-by: Marek Vasut <marex@denx.de> Cc: Chen Peter <redacted> Cc: Greg KH <redacted> Cc: Jiri Kosina <redacted>
I have not admit I don't remember where the original limit came from -- the spec doesn't mandate it as far as I can tell. I am queueing this patch now for next merge window. Thanks.
quoted hunk ↗ jump to hunk
--- drivers/hid/hid-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 60ea284..2b9dd76 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c@@ -374,7 +374,7 @@ static int hid_parser_global(struct hid_parser *parser, struct hid_item *item) case HID_GLOBAL_ITEM_TAG_REPORT_SIZE: parser->global.report_size = item_udata(item); - if (parser->global.report_size > 96) { + if (parser->global.report_size > 128) { hid_err(parser->device, "invalid report_size %d\n", parser->global.report_size); return -1;-- 1.7.10.4
-- Jiri Kosina SUSE Labs