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From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
To: Felipe Balbi <balbi@ti.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-omap@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: AM335x USB DMA seems broken on ISOC URBs
Date: Fri, 17 Jan 2014 13:27:24 -0300	[thread overview]
Message-ID: <20140117162723.GB3843@localhost> (raw)
In-Reply-To: <20131222055945.GA7194@localhost>

On Sun, Dec 22, 2013 at 02:59:45AM -0300, Ezequiel Garcia wrote:
> Hello,
> 
> While doing some experiments with the stk1160 driver (for "Easycap" TV video
> capture devices), ran into problems using v3.13-rc4. The problem is that the
> stk1160 IRQ handler receives no URBs at all.
> 
> When configuring with CONFIG_MUSB_PIO_ONLY this looks solved, but the
> bandwidth requirements are too large for PIO (it's a raw video device) and the
> video can't get captured.
> 
> Interesting enough, using an old backported for v3.2 stk1160 driver, this same
> setup works with TI PSP v3.2 kernel. So, I guess it's some software bug in
> either the cppi41 dmaengine or the musb.
> 
> I tried to compare the PSP to the mainline drivers but they seems *very*
> different and really beyond my understanding.
> 
> Any ideas on how can I help debugging this?
> 

Ping? It would be good to hunt thig bug down. The TI PSP provided USB driver
works fine so at least that's a starting point...

-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
--
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  reply	other threads:[~2014-01-17 16:27 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-22  5:59 AM335x USB DMA seems broken on ISOC URBs Ezequiel Garcia
2014-01-17 16:27 ` Ezequiel Garcia [this message]
2014-01-18 15:12   ` Daniel Mack
2014-01-20 11:15     ` Daniel Mack
     [not found]       ` <52DD055C.1090806-cYrQPVfZoowdnm+yROfE0A@public.gmane.org>
2014-01-20 11:25         ` Ezequiel Garcia
2014-01-20 23:26     ` Ezequiel Garcia

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