Re: [PATCH 2/3] mmc: Export ios settings for a host through debugfs

[Pierre Ossman <drzeus-mmc@drzeus.cx>]

On Thu, 26 Jun 2008 13:09:48 +0200
Haavard Skinnemoen <haavard.skinnemoen@atmel.com> wrote:

> From: Haavard Skinnemoen <hskinnemoen@atmel.com>
> 
> Export all the fields in struct mmc_ios under /sys/kernel/debug/<host>/ios
> 
> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
> ---
>  drivers/mmc/core/host.c  |   55 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mmc/host.h |   13 +++++++++++
>  2 files changed, 68 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 93da502..2977f26 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -25,6 +25,54 @@
>  #ifdef CONFIG_MMC_DEBUG_FS
>  #include <linux/debugfs.h>
>  
> +static void mmc_remove_ios_debugfs(struct mmc_ios *ios)
> +{
> +	if (ios->dbg_root) {

You can save a bit of indentation if you do:

	if (!ios->dbg_root)
		return;

> +static int mmc_add_ios_debugfs(struct mmc_ios *ios, struct dentry *parent)
> +{
> +	struct dentry *dir;
> +
> +	dir = debugfs_create_dir("ios", parent);
> +	if (!dir)
> +		return -EBUSY;	/* or whatever */

Is it undefined what a NULL return means here? I would have expected an
ERRPTR or ENOMEM.

> +#ifdef CONFIG_MMC_DEBUG_FS
> +	struct dentry		*dbg_root;
> +	struct dentry		*dbg_clock;
> +	struct dentry		*dbg_vdd;
> +	struct dentry		*dbg_bus_mode;
> +	struct dentry		*dbg_chip_select;
> +	struct dentry		*dbg_power_mode;
> +	struct dentry		*dbg_bus_width;
> +	struct dentry		*dbg_timing;
> +#endif

Can't we use debugfs' own bookkeeping to keep track of them? Saves us a
lot of noise in these structures.

-- 
     -- Pierre Ossman

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

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