All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Brown <broonie@kernel.org>
To: Robin Gong <b38343@freescale.com>
Cc: linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org, marex@denx.de,
	shawn.guo@linaro.org, Frank.Li@freescale.com
Subject: Re: [PATCH v5] spi: spi-imx: add DMA support
Date: Wed, 10 Sep 2014 11:21:05 +0100	[thread overview]
Message-ID: <20140910102105.GR2601@sirena.org.uk> (raw)
In-Reply-To: <1410312604-31949-1-git-send-email-b38343@freescale.com>

[-- Attachment #1: Type: text/plain, Size: 727 bytes --]

On Wed, Sep 10, 2014 at 09:30:04AM +0800, Robin Gong wrote:

> +static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
> +			 struct spi_transfer *transfer)
> +{
> +	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
> +
> +	if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
> +	    && (transfer->len > spi_imx->tx_wml))
> +		spi_imx->usedma = true;
> +	else
> +		spi_imx->usedma = false;
> +
> +	return spi_imx->usedma;
> +}

This isn't going to work, anything that looks at the usedma flag will
see the result of the last thing that was checked which may or may not
be the transfer that it's handling.  The driver should check to see if
the core mapped the transfer for DMA.

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: broonie@kernel.org (Mark Brown)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5] spi: spi-imx: add DMA support
Date: Wed, 10 Sep 2014 11:21:05 +0100	[thread overview]
Message-ID: <20140910102105.GR2601@sirena.org.uk> (raw)
In-Reply-To: <1410312604-31949-1-git-send-email-b38343@freescale.com>

On Wed, Sep 10, 2014 at 09:30:04AM +0800, Robin Gong wrote:

> +static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
> +			 struct spi_transfer *transfer)
> +{
> +	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
> +
> +	if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
> +	    && (transfer->len > spi_imx->tx_wml))
> +		spi_imx->usedma = true;
> +	else
> +		spi_imx->usedma = false;
> +
> +	return spi_imx->usedma;
> +}

This isn't going to work, anything that looks at the usedma flag will
see the result of the last thing that was checked which may or may not
be the transfer that it's handling.  The driver should check to see if
the core mapped the transfer for DMA.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140910/b5cff6e2/attachment-0001.sig>

  parent reply	other threads:[~2014-09-10 10:21 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-10  1:30 [PATCH v5] spi: spi-imx: add DMA support Robin Gong
2014-09-10  1:30 ` Robin Gong
2014-09-10  4:16 ` Varka Bhadram
2014-09-10  4:16   ` Varka Bhadram
2014-09-10  5:46   ` Robin Gong
2014-09-10  5:46     ` Robin Gong
2014-09-10  5:46     ` Robin Gong
2014-09-10  8:17 ` Arnd Bergmann
2014-09-10  8:17   ` Arnd Bergmann
2014-09-10  8:17   ` Arnd Bergmann
2014-09-10  8:28   ` Robin Gong
2014-09-10  8:28     ` Robin Gong
2014-09-10  8:28     ` Robin Gong
2014-09-10 10:21 ` Mark Brown [this message]
2014-09-10 10:21   ` Mark Brown
2014-09-10 11:22   ` Robin Gong
2014-09-10 11:22     ` Robin Gong
2014-09-10 11:22     ` Robin Gong
2014-09-10 11:45     ` Mark Brown
2014-09-10 11:45       ` Mark Brown
2014-09-10 11:45       ` Mark Brown
2014-09-10 15:18       ` Robin Gong
2014-09-10 15:18         ` Robin Gong
2014-09-10 15:18         ` Robin Gong
2014-09-10 15:52         ` Mark Brown
2014-09-10 15:52           ` Mark Brown
2014-09-10 15:52           ` Mark Brown
2014-09-11  1:37           ` Robin Gong
2014-09-11  1:37             ` Robin Gong

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=20140910102105.GR2601@sirena.org.uk \
    --to=broonie@kernel.org \
    --cc=Frank.Li@freescale.com \
    --cc=b38343@freescale.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=marex@denx.de \
    --cc=shawn.guo@linaro.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.