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Date: Thu, 30 Mar 2017 08:12:22 +0100
From: Sean Young <sean@mess.org>
To: A Sun <as1033x@comcast.net>
Cc: linux-media@vger.kernel.org,
        Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Subject: Re: [PATCH 1/3] [media] mceusb: RX -EPIPE (urb status = -32) lockup
 failure fix
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On Wed, Mar 29, 2017 at 06:04:58PM -0400, A Sun wrote:
> On 3/29/2017 5:06 PM, Sean Young wrote:
> <snip>
> > 
> > Anyway, you're right and this patch looks ok. It would be nice to have the
> > tx case handled too though.
> > 
> > Thanks
> > Sean
> > 
> 
> Thanks; I'm looking at handling the tx case. If I can figure out the details, I'll post a new patch proposal separate, and likely dependent, on this one.
> 
> My main obstacle at the moment, is I'm looking for a way to get mceusb device to respond with a USB TX error halt/stall (rather than the typical ACK and NAK) on a TX endpoint, in order to test halt/stall error detection and recovery for TX. ..A Sun

If you send IR, the drivers send a usb packet. However, the kernel will
sleep for however long the IR is in ir_lirc_transmit_ir, so your other option
is to set the transmit carrier repeatedly instead. You'd have to set the
carrier to a different value every time.


{
	int fd, carrier;

	fd = open("/dev/lirc0", O_RDWR);
	carrier = 38000;
	for (;;) {
		ioctl(fd, LIRC_SET_SEND_CARRIER, &carrier);
		if (++carrier >= 40000)
			carrier = 38000;
	}
}


Sean