From: Vignesh R <vigneshr-l0cyMroinI0@public.gmane.org>
To: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: <linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH v2 2/2] spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble
Date: Tue, 25 Apr 2017 17:48:53 +0530 [thread overview]
Message-ID: <3955ad22-28a2-5222-4ae3-aa34dc69cde6@ti.com> (raw)
In-Reply-To: <20170421170655.dpyxlwipfwnwjjwy-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
On Friday 21 April 2017 10:36 PM, Mark Brown wrote:
> On Tue, Apr 11, 2017 at 05:22:25PM +0530, Vignesh R wrote:
>> Flash filesystems like JFFS2, UBIFS and MTD block layer can provide
>> vmalloc'd or kmap'd buffers that cannot be mapped using dma_map_sg() and
>> can potentially be in memory region above 32bit addressable region(ie
>> buffers belonging to memory region backed by LPAE) of DMA, implement
>> spi_flash_can_dma() interface to inform SPI core not to map such
>> buffers.
>
> I'll apply this since it fixes bugs for your systems but it feels like
> something that we should be moving further into the core since LPAE
> isn't specific to your devices. We should ideally have something
> (possibly in the DMA mapping code even) which does the remapping without
> the driver needing to know about it.
>
I agree, there is a need to have generic remapping code. Also, I guess,
once UBIFS is moved to use kmalloc'd buffers SPI flash devices will not
have to worry much about vmalloc'd buffers.
--
Regards
Vignesh
--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2017-04-25 12:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-11 11:52 [PATCH v2 0/2] spi-ti-qspi: Handle vmalloc'd buffers Vignesh R
[not found] ` <20170411115225.31709-1-vigneshr-l0cyMroinI0@public.gmane.org>
2017-04-11 11:52 ` [PATCH v2 1/2] spi: Add can_dma like interface for spi_flash_read Vignesh R
2017-04-11 11:52 ` [PATCH v2 2/2] spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble Vignesh R
2017-04-21 17:06 ` Mark Brown
[not found] ` <20170421170655.dpyxlwipfwnwjjwy-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2017-04-25 12:18 ` Vignesh R [this message]
[not found] ` <3955ad22-28a2-5222-4ae3-aa34dc69cde6-l0cyMroinI0@public.gmane.org>
2017-06-16 15:54 ` Cyrille Pitchen
2017-06-20 9:45 ` Vignesh R
2017-06-23 12:12 ` Mark Brown
2017-04-21 17:28 ` Applied "spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble" to the spi tree Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3955ad22-28a2-5222-4ae3-aa34dc69cde6@ti.com \
--to=vigneshr-l0cymroini0@public.gmane.org \
--cc=broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).