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From: matthieu.castet@parrot.com (Matthieu CASTET)
To: linux-arm-kernel@lists.infradead.org
Subject: Problem with non aligned DMA in usbnet on ARM
Date: Thu, 12 Aug 2010 19:01:20 +0200	[thread overview]
Message-ID: <4C6428E0.8040402@parrot.com> (raw)
In-Reply-To: <4C6324B2.2080606@gmail.com>

Martin Fuzzey a ?crit :
> Greg KH wrote:
>> Can you fix this in the host controller driver?
>>
>>   
> Technically yes (by copying the unaligned buffers).
> 
> But if we do decide that USB must support unaligned buffers wouldn't it
> be better to have the HCD indicate it's alignment requirement to the
> core and have the core do the copying?
> 
> Gary King sent a message to this thread but only to the arm list saying
> he has the same problem with the tegra hcd (which doesn't seem to be in
> the tree yet.)  I don't know if any of the other in tree HCDs have this
> problem.
dwc otg also got this limitation. I don't know if the version submitted 
for inclusion handle unaligned buffers.


Matthieu

WARNING: multiple messages have this Message-ID (diff)
From: Matthieu CASTET <matthieu.castet@parrot.com>
To: "mfuzzey@gmail.com" <mfuzzey@gmail.com>
Cc: Greg KH <greg@kroah.com>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	linux-usb <linux-usb@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>, <fchen@apm.com>
Subject: Re: Problem with non aligned DMA in usbnet on ARM
Date: Thu, 12 Aug 2010 19:01:20 +0200	[thread overview]
Message-ID: <4C6428E0.8040402@parrot.com> (raw)
In-Reply-To: <4C6324B2.2080606@gmail.com>

Martin Fuzzey a écrit :
> Greg KH wrote:
>> Can you fix this in the host controller driver?
>>
>>   
> Technically yes (by copying the unaligned buffers).
> 
> But if we do decide that USB must support unaligned buffers wouldn't it
> be better to have the HCD indicate it's alignment requirement to the
> core and have the core do the copying?
> 
> Gary King sent a message to this thread but only to the arm list saying
> he has the same problem with the tegra hcd (which doesn't seem to be in
> the tree yet.)  I don't know if any of the other in tree HCDs have this
> problem.
dwc otg also got this limitation. I don't know if the version submitted 
for inclusion handle unaligned buffers.


Matthieu

  reply	other threads:[~2010-08-12 17:01 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-11  9:41 Problem with non aligned DMA in usbnet on ARM Martin Fuzzey
2010-08-11  9:41 ` Martin Fuzzey
2010-08-11  9:54 ` Russell King - ARM Linux
2010-08-11  9:54   ` Russell King - ARM Linux
2010-08-11 10:11   ` Martin Fuzzey
2010-08-11 10:11     ` Martin Fuzzey
2010-08-11 15:04     ` Greg KH
2010-08-11 15:04       ` Greg KH
2010-08-11 16:08       ` Martin Fuzzey
2010-08-11 16:08         ` Martin Fuzzey
2010-08-11 17:42         ` Greg KH
2010-08-11 17:42           ` Greg KH
2010-08-11 19:07           ` Martin Fuzzey
2010-08-11 19:07             ` Martin Fuzzey
2010-08-11 20:13             ` Greg KH
2010-08-11 20:13               ` Greg KH
2010-08-11 22:31               ` Martin Fuzzey
2010-08-11 22:31                 ` Martin Fuzzey
2010-08-12 17:01                 ` Matthieu CASTET [this message]
2010-08-12 17:01                   ` Matthieu CASTET
2010-08-11 19:10           ` Oliver Neukum
2010-08-11 19:10             ` Oliver Neukum
2010-08-11  9:59 ` Matthieu CASTET
2010-08-11  9:59   ` Matthieu CASTET
2010-08-11 11:38   ` Martin Fuzzey
2010-08-11 11:38     ` Martin Fuzzey
2010-08-11 15:54     ` Gary King
2010-08-11 20:35       ` Russell King - ARM Linux
2010-08-11 22:20         ` Martin Fuzzey
2010-08-11 22:20           ` Martin Fuzzey
2010-08-11 22:47           ` Russell King - ARM Linux
2010-08-11 22:47             ` Russell King - ARM Linux
2010-08-12 17:08           ` Matthieu CASTET
2010-08-12 17:08             ` Matthieu CASTET
2010-08-13 10:06             ` Martin Fuzzey
2010-08-13 10:06               ` Martin Fuzzey
2010-08-13 10:58               ` Oliver Neukum
2010-08-13 10:58                 ` Oliver Neukum
2010-08-13 13:42                 ` David Brownell
2010-08-13 13:42                   ` David Brownell
2010-08-13 13:53                   ` Oliver Neukum
2010-08-13 13:53                     ` Oliver Neukum

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