Re: [PATCH 05/18] MMC: OMAP: Introduce new multislot structure andchange driver to use it

From: Pierre Ossman
Date: Thu Feb 07 2008 - 12:38:49 EST


On Mon, 28 Jan 2008 15:07:23 -0400
Carlos Aguiar <carlos.aguiar@xxxxxxxxxxx> wrote:

> From: Juha Yrjola <juha.yrjola@xxxxxxxxxxxxx>
>
> Introduce new MMC multislot structure and change driver to use it.
>
> Note that MMC clocking is now enabled in mmc_omap_select_slot()
> and disabled in mmc_omap_release_slot().
>
> Signed-off-by: Juha Yrjola <juha.yrjola@xxxxxxxxxxxxx>
> Signed-off-by: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx>
> Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar@xxxxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---

I still think this muxed mmc host thing is a bad idea, but it's your nightmare...

> +
> +/* Access to the R/O switch is required for production testing
> + * purposes. */
> +static ssize_t
> +mmc_omap_show_ro(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct mmc_host *mmc = container_of(dev, struct mmc_host, class_dev);
> + struct mmc_omap_slot *slot = mmc_priv(mmc);
> +
> + return sprintf(buf, "%d\n", slot->pdata->get_ro(mmc_dev(mmc),
> + slot->id));
> +}
> +
> +static DEVICE_ATTR(ro, S_IRUGO, mmc_omap_show_ro, NULL);
> +

This is unrelated to the slot stuff and should be in its own patch. Also, it should probably be in the core, not a driver.

> +
> + mmc->caps = MMC_CAP_MULTIWRITE | MMC_CAP_MMC_HIGHSPEED |
> + MMC_CAP_SD_HIGHSPEED;

This is also unrelated. From what I've seen, the OMAP is a SD controller and does not support high speed MMC. The fact that you also conditionally set the max frequency later also suggests that this code is entirely incorrect.

> +
> + r = mmc_add_host(mmc);
> + if (r < 0)
> + return r;
> +
> + if (slot->pdata->name != NULL) {
> + r = device_create_file(&mmc->class_dev,
> + &dev_attr_slot_name);
> + if (r < 0)
> + goto err_remove_host;
> + }
> +
> + if (slot->pdata->get_ro != NULL) {
> + r = device_create_file(&mmc->class_dev,
> + &dev_attr_ro);
> + }
> +

You have a bit of a race here with userspace in case you use the uevent to trigger things.

--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org
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