From: Maxime Ripard <maxime.ripard@free-electrons.com>
To: Michal Suchanek <hramrach@gmail.com>
Cc: linux-sunxi@googlegroups.com, Rob Herring <robh+dt@kernel.org>,
Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Russell King <linux@arm.linux.org.uk>,
Mark Brown <broonie@kernel.org>,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org
Subject: Re: [PATCH 2/9] spi: sun4i: fix FIFO limit
Date: Thu, 20 Aug 2015 16:45:52 +0200 [thread overview]
Message-ID: <20150820144552.GU30520@lukather> (raw)
In-Reply-To: <a40fbf7ca8bd36f08f5e9d3fb6f6de2454066af7.1440080122.git.hramrach@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1702 bytes --]
On Thu, Aug 20, 2015 at 02:19:46PM -0000, Michal Suchanek wrote:
> When testing SPI without DMA I noticed that filling the FIFO on the
> spi controller causes timeout.
>
> Always leave room for one byte in the FIFO.
>
> Signed-off-by: Michal Suchanek <hramrach@gmail.com>
> ---
> drivers/spi/spi-sun4i.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
> index 48532ec..707f61b 100644
> --- a/drivers/spi/spi-sun4i.c
> +++ b/drivers/spi/spi-sun4i.c
> @@ -178,6 +178,8 @@ static int sun4i_spi_transfer_one(struct spi_master *master,
> /* We don't support transfer larger than the FIFO */
> if (tfr->len > SUN4I_FIFO_DEPTH)
> return -EINVAL;
> + if (tfr->tx_buf && tfr->len => SUN4I_FIFO_DEPTH)
> + return -EINVAL;
Shouldn't you fix the condition just above instead?
>
> reinit_completion(&sspi->done);
> sspi->tx_buf = tfr->tx_buf;
> @@ -271,7 +273,9 @@ static int sun4i_spi_transfer_one(struct spi_master *master,
> sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len));
>
> /* Fill the TX FIFO */
> - sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH);
> + /* Filling the fifo fully causes timeout for some reason
> + * at least on spi2 on a10s */
Please use the proper comment style. And it only happens on that
particular SPI controller and SoC combination?
> + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH - 1);
>
> /* Enable the interrupts */
> sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, SUN4I_INT_CTL_TC);
> --
> 2.1.4
>
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
next prev parent reply other threads:[~2015-08-20 14:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1440080122.git.hramrach@gmail.com>
[not found] ` <0e0b52774a48ddb71dc8095b66942451cd31ff7d.1440080122.git.hramrach@gmail.com>
2015-08-20 14:43 ` [PATCH 1/9] spi: sunxi: fix transfer timeout Maxime Ripard
2015-08-20 18:41 ` Mark Brown
2015-08-20 19:34 ` Maxime Ripard
2015-08-20 21:08 ` Mark Brown
2015-08-20 21:18 ` Maxime Ripard
2015-08-20 21:29 ` Mark Brown
[not found] ` <a40fbf7ca8bd36f08f5e9d3fb6f6de2454066af7.1440080122.git.hramrach@gmail.com>
2015-08-20 14:45 ` Maxime Ripard [this message]
[not found] ` <ccf776869b0d7fe2c78bcc41d6cd1896bf732296.1440080122.git.hramrach@gmail.com>
2015-08-20 14:24 ` [linux-sunxi] [PATCH 4/9] spi: sun4i: add DMA support Michal Suchanek
2015-08-20 14:56 ` Maxime Ripard
2015-08-20 18:58 ` Mark Brown
2016-05-17 5:44 ` [linux-sunxi] " Michal Suchanek
2015-08-20 19:00 ` Mark Brown
[not found] ` <a5a061d98b7ff851866cc668cd8bf8f6fc99d002.1440080122.git.hramrach@gmail.com>
2015-08-20 14:58 ` [PATCH 5/9] ARM: dts: sun7i: cubieboard2: Enable SPI0 Maxime Ripard
[not found] ` <90730047894f6ec84cd70062a27b7085c2016260.1440080122.git.hramrach@gmail.com>
2015-08-20 15:00 ` [PATCH 7/9] ARM: dts: sun5i: add SPI pins on A13 and A10s Maxime Ripard
[not found] ` <3688fab67e7cdc7bcbff73dfd6b0fcdcc4e79eb6.1440080122.git.hramrach@gmail.com>
2015-08-20 14:48 ` [PATCH 3/9] spi: sunxi: check that transfer speed is non-zero Maxime Ripard
2015-08-20 19:45 ` Michal Suchanek
2015-08-20 21:23 ` Maxime Ripard
2015-08-20 18:45 ` 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=20150820144552.GU30520@lukather \
--to=maxime.ripard@free-electrons.com \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=galak@codeaurora.org \
--cc=hramrach@gmail.com \
--cc=ijc+devicetree@hellion.org.uk \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=linux@arm.linux.org.uk \
--cc=mark.rutland@arm.com \
--cc=pawel.moll@arm.com \
--cc=robh+dt@kernel.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).