From: Felipe Balbi <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
To: "ext Gupta, Ajay Kumar" <ajay.gupta-l0cyMroinI0@public.gmane.org>
Cc: "me-uiRdBs8odbtmTBlB0Cgj/Q@public.gmane.org"
<me-uiRdBs8odbtmTBlB0Cgj/Q@public.gmane.org>,
"linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH 4/5] musb: use system DMA for unaligned buffers on RTL >= 1.8
Date: Fri, 14 May 2010 14:06:48 +0300 [thread overview]
Message-ID: <20100514110648.GA3947@nokia.com> (raw)
In-Reply-To: <19F8576C6E063C45BE387C64729E7394044E405169-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org>
On Thu, May 13, 2010 at 06:13:00AM +0200, ext Gupta, Ajay Kumar wrote:
>How about this 'memcpy', this would affect both cpu loading
>and performance. That's why using system dma would be a better
>approach.
but that's not portable. Even if you come up with nice wrappers for
system dma usage (which is already ugly, more exported functions) you
might end up on a board where system dma has same alignment constraints
as mentor dma. Either fall back to pio or use a bounce buffer. That'll
work always.
Besides, the only offending gadget driver we have is g_ether and that's
already 'fixed' by the alignment patch to g_ether. Any other gadget
driver causing that, should be fixed too...
--
balbi
DefectiveByDesign.org
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next prev parent reply other threads:[~2010-05-14 11:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-12 11:49 [PATCH 1/5] musb: save OTG base physical address Ajay Kumar Gupta
2010-05-12 11:49 ` [PATCH 2/5] musb: use system DMA to fix Inventra DMA issue on RTL-1.4 Ajay Kumar Gupta
[not found] ` <1273664979-493-2-git-send-email-ajay.gupta-l0cyMroinI0@public.gmane.org>
2010-05-12 11:49 ` [PATCH 3/5] musb: add function to check if Inventra DMA used Ajay Kumar Gupta
[not found] ` <1273664979-493-3-git-send-email-ajay.gupta-l0cyMroinI0@public.gmane.org>
2010-05-12 11:49 ` [PATCH 4/5] musb: use system DMA for unaligned buffers on RTL >= 1.8 Ajay Kumar Gupta
[not found] ` <1273664979-493-4-git-send-email-ajay.gupta-l0cyMroinI0@public.gmane.org>
2010-05-12 11:49 ` [PATCH 5/5] musb: dma: use optimal transfer element for sdma Ajay Kumar Gupta
2010-05-12 13:18 ` [PATCH 4/5] musb: use system DMA for unaligned buffers on RTL >= 1.8 Sergei Shtylyov
2010-05-12 13:55 ` Gupta, Ajay Kumar
2010-05-12 14:59 ` Sergei Shtylyov
[not found] ` <4BEAC268.1080601-hkdhdckH98+B+jHODAdFcQ@public.gmane.org>
2010-05-12 17:55 ` Felipe Balbi
2010-05-13 4:14 ` Gupta, Ajay Kumar
[not found] ` <19F8576C6E063C45BE387C64729E7394044E40516A-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org>
2010-05-13 19:43 ` Felipe Balbi
2010-05-14 4:39 ` Gupta, Ajay Kumar
2010-05-12 17:54 ` Felipe Balbi
2010-05-13 4:13 ` Gupta, Ajay Kumar
[not found] ` <19F8576C6E063C45BE387C64729E7394044E405169-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org>
2010-05-14 11:06 ` Felipe Balbi [this message]
2010-05-14 11:39 ` Gupta, Ajay Kumar
2010-05-12 17:52 ` [PATCH 3/5] musb: add function to check if Inventra DMA used Felipe Balbi
2010-05-12 17:51 ` [PATCH 2/5] musb: use system DMA to fix Inventra DMA issue on RTL-1.4 Felipe Balbi
2010-05-12 17:56 ` Gadiyar, Anand
[not found] ` <5A47E75E594F054BAF48C5E4FC4B92AB03216237DA-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org>
2010-05-13 4:22 ` Gupta, Ajay Kumar
2010-05-13 8:58 ` Kalliguddi, Hema
2010-05-13 10:10 ` Gupta, Ajay Kumar
2010-05-13 11:57 ` Kalliguddi, Hema
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