From: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
To: Laxman Dewangan <ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org,
grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org,
swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] spi: tegra: slink: do not prepare dma transfer with DMA_CTRL_ACK flag
Date: Mon, 26 Nov 2012 15:03:23 -0700 [thread overview]
Message-ID: <50B3E72B.6020003@wwwdotorg.org> (raw)
In-Reply-To: <1353662559-26515-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
On 11/23/2012 02:22 AM, Laxman Dewangan wrote:
> Spi starts transfer using dma with DMA_CTRL_ACK which is not require
> becasue spi driver does not use completed dma_desc after transfer
> done and so it does not ack the dma descriptor. Removing the
> DMA_CTRL_ACK flag to avoid memory leak in dma driver.
I'm not quite sure, but isn't this the opposite of what's wanted. I
think that setting this flag in prep() means that the SPI driver need
not explicitly ack it later?
At least, tegra_dma_desc_get() returns an allocated descriptor if one
exists and async_tx_test_ack()==true for it, and it's true when the
DMA_CTRL_ACK flag is set, which happens either due to calling
async_tx_ack(), or because tegra_dma_prep_slave_sg() was called with
DMA_CTRL_ACK in flags.
next prev parent reply other threads:[~2012-11-26 22:03 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-23 9:22 [PATCH] spi: tegra: slink: do not prepare dma transfer with DMA_CTRL_ACK flag Laxman Dewangan
2012-11-23 9:22 ` Laxman Dewangan
[not found] ` <1353662559-26515-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2012-11-26 22:03 ` Stephen Warren [this message]
[not found] ` <50B3E72B.6020003-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2012-11-26 23:00 ` Laxman Dewangan
2013-04-01 13:35 ` Mark Brown
[not found] ` <20130401133459.GS18636-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
2013-04-03 9:31 ` Laxman Dewangan
[not found] ` <515BF6ED.2060904-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-04-03 17:36 ` Mark Brown
2013-04-03 9:31 ` Laxman Dewangan
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=50B3E72B.6020003@wwwdotorg.org \
--to=swarren-3lzwwm7+weoh9zmkesr00q@public.gmane.org \
--cc=broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org \
--cc=grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org \
--cc=ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
--cc=linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org \
--cc=swarren-DDmLM1+adcrQT0dZR+AlfA@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.