Re: [RFC PATCH 37/40] soundwire: cadence_master: add hw_reset capability in debugfs

Greg KH
2019-07-26T14:07:54Z

On Thu, Jul 25, 2019 at 06:40:29PM -0500, Pierre-Louis Bossart wrote:
> This is to kick devices into reset and see what software does
>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> ---
> drivers/soundwire/cadence_master.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
> index fa7230b0f200..53278aa2436f 100644
> --- a/drivers/soundwire/cadence_master.c
> +++ b/drivers/soundwire/cadence_master.c
> @@ -331,6 +331,25 @@ static const struct file_operations cdns_reg_fops = {
> .llseek = default_llseek,
> };
>
> +static int cdns_hw_reset(void *data, u64 value)
> +{
> + struct sdw_cdns *cdns = data;
> + int ret;
> +
> + if (value != 1)
> + return 0;
> +
> + dev_info(cdns->dev, "starting link hw_reset\n");
> +
> + ret = sdw_cdns_exit_reset(cdns);
> +
> + dev_info(cdns->dev, "link hw_reset done\n");

Do not be noisy for when things always go right. This looks like
debuggging code, please remove.

> +
> + return ret;
> +}
> +
> +DEFINE_DEBUGFS_ATTRIBUTE(cdns_hw_reset_fops, NULL, cdns_hw_reset, "%llu\n");
> +
> /**
> * sdw_cdns_debugfs_init() - Cadence debugfs init
> * @cdns: Cadence instance
> @@ -339,6 +358,9 @@ static const struct file_operations cdns_reg_fops = {
> void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
> {
> debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);
> +
> + debugfs_create_file_unsafe("cdns-hw-reset", 0200, root, cdns,
> + &cdns_hw_reset_fops);

Why unsafe?

thanks,

greg k-h