From: Trent Piepho <tpiepho@gmail.com>
To: Sourav Poddar <sourav.poddar@ti.com>
Cc: Peter Korsgaard <peter@korsgaard.com>,
"Balbi, Felipe" <balbi@ti.com>, Mark Brown <broonie@kernel.org>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"Gupta, Pekon" <pekon@ti.com>,
"spi-devel-general@lists.sourceforge.net"
<spi-devel-general@lists.sourceforge.net>,
Brian Norris <computersforpeace@gmail.com>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH 1/3] spi/qspi: Add memory mapped read support.
Date: Thu, 17 Oct 2013 22:56:53 -0700 [thread overview]
Message-ID: <CA+7tXihUBXK61cRDmn3tnY9FM7FUSZrhPpLry2VAfvwWJpJ6gQ@mail.gmail.com> (raw)
In-Reply-To: <5260B3AE.9070308@ti.com>
On Thu, Oct 17, 2013 at 9:06 PM, Sourav Poddar <sourav.poddar@ti.com> wrote:
> On Friday 18 October 2013 05:12 AM, Mark Brown wrote:
>>> Are you looking for comparison between read_via_dma() v/s memcpy() ?
>>
>> No, I'm looking for a comparison of normal SPI mode (which I'd have
>> expected to DMA) and the memcpy() mode.
>>
>>> If yes, then unfortunately we are bit constrained because our controller
>>> does not support DMA. So, we have to depend on CPU based memcpy()
>>> only. However, use of DMA can be added as an independent patch on
>>> top of this CASE-2 patch.
>>
>> However if the controller can't DMA at all then that's not going to be
>> possible... am I understanding you correctly that normal SPI can't DMA?
>
> Yes, you are correct, the normal SPI cant DMA.
Hardware limitation or driver limitation? Adding DMA support to the
driver might be much more useful than adding memory mapped read
support.
next prev parent reply other threads:[~2013-10-18 5:57 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-09 15:24 [PATCH 0/3]Add quad/memory mapped support for SPI flash Sourav Poddar
2013-10-09 15:24 ` Sourav Poddar
2013-10-09 15:24 ` [PATCH 1/3] spi/qspi: Add memory mapped read support Sourav Poddar
2013-10-09 15:24 ` Sourav Poddar
2013-10-09 16:07 ` Mark Brown
2013-10-09 16:07 ` Mark Brown
[not found] ` <20131009160759.GQ21581-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2013-10-09 16:54 ` Sourav Poddar
2013-10-09 16:54 ` Sourav Poddar
2013-10-09 17:40 ` Mark Brown
2013-10-09 17:40 ` Mark Brown
2013-10-09 18:15 ` Sourav Poddar
2013-10-09 18:15 ` Sourav Poddar
2013-10-09 18:41 ` Mark Brown
2013-10-09 18:41 ` Mark Brown
[not found] ` <20131009174027.GS21581-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2013-10-09 19:01 ` Peter Korsgaard
2013-10-09 19:01 ` Peter Korsgaard
2013-10-09 19:36 ` Mark Brown
2013-10-09 19:36 ` Mark Brown
[not found] ` <87hacq1d5k.fsf-D6SC8u56vOOJDPpyT6T3/w@public.gmane.org>
2013-10-10 2:27 ` Trent Piepho
2013-10-10 2:27 ` Trent Piepho
2013-10-10 8:52 ` Sourav Poddar
2013-10-10 8:52 ` Sourav Poddar
2013-10-10 10:14 ` Mark Brown
2013-10-10 10:14 ` Mark Brown
2013-10-10 10:17 ` Sourav Poddar
2013-10-10 10:17 ` Sourav Poddar
2013-10-10 11:08 ` Sourav Poddar
2013-10-10 11:08 ` Sourav Poddar
2013-10-11 10:08 ` Mark Brown
2013-10-11 10:08 ` Mark Brown
2013-10-15 6:06 ` Sourav Poddar
2013-10-15 6:06 ` Sourav Poddar
2013-10-15 11:16 ` Mark Brown
2013-10-15 11:16 ` Mark Brown
2013-10-15 11:49 ` Sourav Poddar
2013-10-15 11:49 ` Sourav Poddar
2013-10-15 12:46 ` Mark Brown
2013-10-15 12:46 ` Mark Brown
[not found] ` <20131015124656.GM2443-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2013-10-15 13:23 ` Sourav Poddar
2013-10-15 13:23 ` Sourav Poddar
2013-10-15 15:53 ` Mark Brown
2013-10-15 15:53 ` Mark Brown
[not found] ` <525D41E2.30206-l0cyMroinI0@public.gmane.org>
2013-10-15 15:33 ` Gupta, Pekon
2013-10-15 15:33 ` Gupta, Pekon
2013-10-15 16:01 ` Mark Brown
2013-10-15 16:01 ` Mark Brown
2013-10-15 16:54 ` Gupta, Pekon
2013-10-15 16:54 ` Gupta, Pekon
2013-10-15 18:01 ` Brian Norris
2013-10-15 18:01 ` Brian Norris
2013-10-15 18:10 ` Sourav Poddar
2013-10-15 18:10 ` Sourav Poddar
[not found] ` <20131015180142.GS23337-bU/DPfM3abD4WzifrMjOTkcViWtcw2C0@public.gmane.org>
2013-10-15 18:13 ` Trent Piepho
2013-10-15 18:13 ` Trent Piepho
2013-10-15 18:33 ` Gupta, Pekon
2013-10-15 18:33 ` Gupta, Pekon
2013-10-15 20:52 ` Mark Brown
2013-10-15 20:52 ` Mark Brown
[not found] ` <20131015205254.GX2443-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2013-10-15 21:03 ` Trent Piepho
2013-10-15 21:03 ` Trent Piepho
2013-10-15 22:10 ` Mark Brown
2013-10-15 22:10 ` Mark Brown
[not found] ` <20980858CB6D3A4BAE95CA194937D5E73EA23640-yXqyApvAXouIQmiDNMet8wC/G2K4zDHf@public.gmane.org>
2013-10-17 12:24 ` Sourav Poddar
2013-10-17 12:24 ` Sourav Poddar
2013-10-17 12:38 ` Mark Brown
2013-10-17 12:38 ` Mark Brown
2013-10-17 13:03 ` Gupta, Pekon
2013-10-17 13:03 ` Gupta, Pekon
2013-10-17 23:42 ` Mark Brown
2013-10-18 4:06 ` Sourav Poddar
2013-10-18 5:56 ` Trent Piepho [this message]
2013-10-18 6:10 ` Sourav Poddar
2013-10-18 7:27 ` Sourav Poddar
2013-10-18 10:31 ` Mark Brown
2013-10-18 11:48 ` Sourav Poddar
2013-10-18 13:08 ` Mark Brown
2013-10-18 14:47 ` Sourav Poddar
2013-10-15 20:59 ` Mark Brown
2013-10-15 20:59 ` Mark Brown
[not found] ` <52566ACC.1080100-l0cyMroinI0@public.gmane.org>
2013-10-11 9:30 ` Gupta, Pekon
2013-10-11 9:30 ` Gupta, Pekon
2013-10-10 10:10 ` Mark Brown
2013-10-10 10:10 ` Mark Brown
[not found] ` <20131010101052.GF21581-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2013-10-10 23:53 ` Trent Piepho
2013-10-11 9:59 ` Mark Brown
2013-10-11 9:59 ` Mark Brown
2013-10-09 15:24 ` [PATCHv3 2/3] drivers: mtd: devices: Add quad " Sourav Poddar
2013-10-09 15:24 ` Sourav Poddar
[not found] ` <1381332284-21822-3-git-send-email-sourav.poddar-l0cyMroinI0@public.gmane.org>
2013-10-09 18:15 ` Jagan Teki
2013-10-09 18:15 ` Jagan Teki
[not found] ` <CAD6G_RShZMkSpVzvXWEE0+sDX=pcnf7ndChndgDG5_T4EVL2vQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-10-11 7:10 ` Gupta, Pekon
2013-10-11 7:10 ` Gupta, Pekon
2013-10-24 1:06 ` Brian Norris
2013-10-24 5:44 ` Sourav Poddar
2013-10-24 7:34 ` Brian Norris
2013-10-24 8:44 ` Sourav Poddar
2013-10-24 17:07 ` Brian Norris
2013-10-24 17:55 ` Sourav Poddar
2013-10-09 15:24 ` [RFC/PATCH 3/3] drivers: mtd: devices: Add memory mapped " Sourav Poddar
2013-10-09 15:24 ` Sourav Poddar
2013-10-09 15:45 ` Mark Brown
2013-10-09 15:45 ` Mark Brown
2013-10-24 0:22 ` [PATCH 0/3]Add quad/memory mapped support for SPI flash Brian Norris
2013-10-24 4:51 ` Sourav Poddar
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