On 16-09-19, 14:09, Pierre-Louis Bossart wrote:
> Provide debugfs capability to kick link and devices into hard-reset
> (as defined by MIPI). This capability is really useful when some
> devices are no longer responsive and/or to check the software handling
> of resynchronization.
>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> ---
> drivers/soundwire/cadence_master.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
> index e3d06330d125..5f900cf2acb9 100644
> --- a/drivers/soundwire/cadence_master.c
> +++ b/drivers/soundwire/cadence_master.c
> @@ -340,6 +340,23 @@ static int cdns_reg_show(struct seq_file *s, void *data)
> }
> DEFINE_SHOW_ATTRIBUTE(cdns_reg);
>
> +static int cdns_hw_reset(void *data, u64 value)
> +{
> + struct sdw_cdns *cdns = data;
> + int ret;
> +
> + if (value != 1)
> + return -EINVAL;
> +
> + ret = sdw_cdns_exit_reset(cdns);
So we are performing reset of the device behind the kernel, so I think
it makes sense to mark the kernel as tainted.
> +
> + dev_dbg(cdns->dev, "link hw_reset done: %d\n", ret);
> +
> + return ret;
We may want to get rid of the debug and do:
return sdw_cdns_exit_reset();
> +}
> +
> +DEFINE_DEBUGFS_ATTRIBUTE(cdns_hw_reset_fops, NULL, cdns_hw_reset, "%llu\n");
> +
> /**
> * sdw_cdns_debugfs_init() - Cadence debugfs init
> * @cdns: Cadence instance
> @@ -348,6 +365,9 @@ DEFINE_SHOW_ATTRIBUTE(cdns_reg);
> 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("cdns-hw-reset", 0200, root, cdns,
> + &cdns_hw_reset_fops);
> }
> EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);
>
> --
> 2.20.1
--
~Vinod
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