From: Rob Herring <robh@kernel.org>
To: Jun Nie <jun.nie@linaro.org>
Cc: ulf.hansson@linaro.org, mark.rutland@arm.com,
adrian.hunter@intel.com, linux-mmc@vger.kernel.org,
devicetree@vger.kernel.org
Subject: Re: [PATCH 2/4] mmc: sdhci: dt: Add DMA boundary and HS400 properties
Date: Fri, 13 Dec 2019 17:01:38 -0600 [thread overview]
Message-ID: <20191213230137.GA15696@bogus> (raw)
In-Reply-To: <20191202144104.5069-3-jun.nie@linaro.org>
On Mon, Dec 02, 2019 at 10:41:02PM +0800, Jun Nie wrote:
> DMA memory cannot cross specific boundary on some controller, such as 128MB
> on SDHCI Designware. Add sdhci-dma-mem-boundary property to split DMA
> operation in such case.
>
> sdhci-ctrl-hs400 specify the HS400 mode setting for register
> SDHCI_HOST_CONTROL2(offset 0x3E:bit[2:0]). Because this value is not
> defined in SDHC Standard specification.
>
> Signed-off-by: Jun Nie <jun.nie@linaro.org>
> ---
> Documentation/devicetree/bindings/mmc/sdhci.txt | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci.txt b/Documentation/devicetree/bindings/mmc/sdhci.txt
> index 0e9923a64024..e6d7feb9a741 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci.txt
> @@ -11,3 +11,11 @@ Optional properties:
> - sdhci-caps: The sdhci capabilities register is incorrect. This 64bit
> property corresponds to the bits in the sdhci capability register. If the
> bit is on in the property then the bit should be turned on.
> +- sdhci-dma-mem-boundary: The sdhci controller DMA memory space boundary.
> + If the controller's DMA cannot cross a specific memory space boundary,
> + such as 128MB, set this value in dt and driver will split the DMA
> + operation when crossing such boundary.
This should be implied by the compatible string.
> +- sdhci-ctrl-hs400: The HS400 is not defined in SDHC Standard specification
> + for SDHCI_HOST_CONTROL2(offset 0x3E:bit[2:0]). Different controllers have
> + have different value for HS400 mode. If 0x5 is not the HS400 mode value
> + for your controller, you should specify the value with this property.
This too, unless it needs to be tuned per board.
Can you be more specific as to what the possible values are and what
they do?
Rob
next prev parent reply other threads:[~2019-12-13 23:01 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 14:41 [PATCH 0/4] mmc: Add sdhci workaround stability enhencement Jun Nie
2019-12-02 14:41 ` [PATCH 1/4] mmc: sdhci: Add delay after power off Jun Nie
2019-12-03 7:26 ` Adrian Hunter
2019-12-02 14:41 ` [PATCH 2/4] mmc: sdhci: dt: Add DMA boundary and HS400 properties Jun Nie
2019-12-13 23:01 ` Rob Herring [this message]
2019-12-17 14:56 ` Jun Nie
2019-12-02 14:41 ` [PATCH 3/4] mmc: sdhci: Set ctrl_hs400 value in dts Jun Nie
2019-12-03 7:52 ` Adrian Hunter
2019-12-02 14:41 ` [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround Jun Nie
2019-12-02 17:52 ` Christoph Hellwig
2019-12-03 3:29 ` Jun Nie
2019-12-03 7:36 ` Christoph Hellwig
2019-12-04 6:00 ` Jun Nie
2019-12-04 7:14 ` Jisheng Zhang
2019-12-10 9:36 ` Ulf Hansson
2019-12-03 2:47 ` Jisheng Zhang
2019-12-03 3:33 ` Jun Nie
2019-12-03 9:05 ` Jisheng Zhang
2019-12-03 9:18 ` Christoph Hellwig
2019-12-03 9:49 ` Jisheng Zhang
2019-12-03 13:06 ` Christoph Hellwig
2019-12-04 7:11 ` Jisheng Zhang
2019-12-03 9:49 ` Jisheng Zhang
2019-12-03 13:04 ` Christoph Hellwig
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=20191213230137.GA15696@bogus \
--to=robh@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=devicetree@vger.kernel.org \
--cc=jun.nie@linaro.org \
--cc=linux-mmc@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=ulf.hansson@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 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).