From: Sascha Hauer <s.hauer@pengutronix.de>
To: Philipp Zabel <p.zabel@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH] mmc: allow skipping SD card initialization
Date: Tue, 26 Sep 2017 08:53:20 +0200 [thread overview]
Message-ID: <20170926065320.ym7c4xqtdrp4zkv6@pengutronix.de> (raw)
In-Reply-To: <20170920155044.1841-1-p.zabel@pengutronix.de>
On Wed, Sep 20, 2017 at 05:50:44PM +0200, Philipp Zabel wrote:
> This patch allows to skip SD card initialization for eMMCs by setting
> the "no-sd" property in the host controller device tree node. Avoiding
> two SD command timeouts speeds up detection time by well over 200 ms.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> drivers/mci/mci-core.c | 12 ++++++++----
> include/mci.h | 1 +
> 2 files changed, 9 insertions(+), 4 deletions(-)
Applied, thanks
Sascha
>
> diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
> index 07911d43d..208b7666d 100644
> --- a/drivers/mci/mci-core.c
> +++ b/drivers/mci/mci-core.c
> @@ -1682,10 +1682,13 @@ static int mci_card_probe(struct mci *mci)
> }
>
> /* Check if this card can handle the "SD Card Physical Layer Specification 2.0" */
> - rc = sd_send_if_cond(mci);
> - rc = sd_send_op_cond(mci);
> - if (rc && rc == -ETIMEDOUT) {
> - /* If the command timed out, we check for an MMC card */
> + if (!host->no_sd) {
> + rc = sd_send_if_cond(mci);
> + rc = sd_send_op_cond(mci);
> + }
> + if (host->no_sd || rc == -ETIMEDOUT) {
> + /* If SD card initialization was skipped or if it timed out,
> + * we check for an MMC card */
> dev_dbg(&mci->dev, "Card seems to be a MultiMediaCard\n");
> rc = mmc_send_op_cond(mci);
> }
> @@ -1904,6 +1907,7 @@ void mci_of_parse_node(struct mci_host *host,
> }
>
> host->non_removable = of_property_read_bool(np, "non-removable");
> + host->no_sd = of_property_read_bool(np, "no-sd");
> }
>
> void mci_of_parse(struct mci_host *host)
> diff --git a/include/mci.h b/include/mci.h
> index d3115e8cc..1f6533391 100644
> --- a/include/mci.h
> +++ b/include/mci.h
> @@ -403,6 +403,7 @@ struct mci_host {
> unsigned dsr_val; /**< optional dsr value */
> int use_dsr; /**< optional dsr usage flag */
> bool non_removable; /**< device is non removable */
> + bool no_sd; /**< do not send SD commands during initialization */
> struct regulator *supply;
>
> /** init the host interface */
> --
> 2.11.0
>
>
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
>
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prev parent reply other threads:[~2017-09-26 6:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-20 15:50 Philipp Zabel
2017-09-26 6:53 ` Sascha Hauer [this message]
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