All of lore.kernel.org
 help / color / mirror / Atom feed
From: nsekhar@ti.com (Sekhar Nori)
To: linux-arm-kernel@lists.infradead.org
Subject: [patch V2 5/6] edma: Make reading the position of active channels work
Date: Mon, 28 Apr 2014 20:14:03 +0530	[thread overview]
Message-ID: <535E6933.2020509@ti.com> (raw)
In-Reply-To: <20140428104643.215725974@linutronix.de>

On Monday 28 April 2014 04:19 PM, Thomas Gleixner wrote:

> As Joel pointed out, edma_read_position() uses memcpy_fromio() to read
> the parameter ram. That's not synchronized with the internal update as
> it does a byte by byte copy. We need to do a 32bit read to get a
> consistent value.
> 
> Further reading destination and source is pointless. In DEV_TO_MEM
> transfers we are only interested in the destination, in MEM_TO_DEV we
> care about the source. In MEM_TO_MEM it really does not matter which
> one you read.
> 
> Simple solution: Remove the pointers, select dest/source via a bool
> and return the read value.

> Remove the export of this function while at it. The only potential
> user is the dmaengine and that's always builtin.

While this is true today, there are other DMA drivers which
are modules.

> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Irrespective of above,

Acked-by: Sekhar Nori <nsekhar@ti.com>

Thanks,
Sekhar

  reply	other threads:[~2014-04-28 14:44 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-28 10:49 [patch V2 0/6] dma: edma: Provide granular residue accounting Thomas Gleixner
2014-04-28 10:49 ` [patch V2 1/6] dma: edma: Sanitize residue reporting Thomas Gleixner
2014-04-28 10:49 ` [patch V2 2/6] dma: edma: Check the current decriptor first in tx_status() Thomas Gleixner
2014-04-28 10:49 ` [patch V2 3/6] dma: edma: Create private pset struct Thomas Gleixner
2014-04-28 10:49 ` [patch V2 4/6] dma: edma: Store transfer data in edma_desc and edma_pset Thomas Gleixner
2014-04-28 10:49 ` [patch V2 5/6] edma: Make reading the position of active channels work Thomas Gleixner
2014-04-28 14:44   ` Sekhar Nori [this message]
2014-04-28 16:11   ` Joel Fernandes
2014-04-28 10:49 ` [patch V2 6/6] dma: edma: Provide granular accounting Thomas Gleixner
2014-04-28 20:47 ` [patch V2 0/6] dma: edma: Provide granular residue accounting Joel Fernandes
2014-04-28 20:47   ` Joel Fernandes
2014-04-29  8:46   ` Vinod Koul
2014-04-29  8:46     ` Vinod Koul
2014-04-30  4:25     ` Joel Fernandes
2014-04-30  4:25       ` Joel Fernandes
2014-04-30  5:08       ` Vinod Koul
2014-04-30  5:08         ` Vinod Koul
2014-05-01  1:57         ` Joel Fernandes
2014-05-01  1:57           ` Joel Fernandes

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=535E6933.2020509@ti.com \
    --to=nsekhar@ti.com \
    --cc=linux-arm-kernel@lists.infradead.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.