On Fri, Oct 08, 2021 at 03:38:21PM +0300, Heikki Krogerus wrote:
> Hi,
>
> On Thu, Oct 07, 2021 at 09:15:12AM -0700, Bjorn Andersson wrote:
> > The one thing that I still don't understand though is, if the typec_mux
> > is used by the typec controller to inform _the_ mux about the function
> > to be used, what's up with the complexity in typec_mux_match()? This is
> > what lead me to believe that typec_mux was enabling/disabling individual
> > altmodes, rather just flipping the physical switch at the bottom.
>
> Ah, typec_mux_match() is a mess. I'm sorry about that. I think most of
> the code in that function is not used by anybody. If I remember
> correctly, all that complexity is attempting to solve some
> hypothetical corner case(s). Probable a case where we have multiple
> muxes per port to deal with.
>
> I think it would probable be best to clean the function to the bare
> minimum by keeping only the parts that are actually used today
> (attached).
>
Sorry for not replying to this in a timely manner Heikki. I've been
ignoring this issue for a long time now, just adding "svid" to our dts
files. But, this obviously shows up in DT validation - and I'd prefer
not defining these properties as valid.
The attached patch works as expected.
Could you please spin this as a proper patch, so we can get it merged?
Regards,
Bjorn
> thanks,
>
> --
> heikki
> diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
> index c8340de0ed495..44f168c9bd9bf 100644
> --- a/drivers/usb/typec/mux.c
> +++ b/drivers/usb/typec/mux.c
> @@ -193,56 +193,15 @@ static int mux_fwnode_match(struct device *dev, const
> void *fwnode)
> static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id,
> void *data)
> {
> - const struct typec_altmode_desc *desc = data;
> struct device *dev;
> - bool match;
> - int nval;
> - u16 *val;
> - int ret;
> - int i;
>
> /*
> - * Check has the identifier already been "consumed". If it
> - * has, no need to do any extra connection identification.
> + * The connection identifier will be needed with device graph (OF
> graph).
> + * Device graph is not supported by this code yet, so bailing out.
> */
> - match = !id;
> - if (match)
> - goto find_mux;
> -
> - /* Accessory Mode muxes */
> - if (!desc) {
> - match = fwnode_property_present(fwnode, "accessory");
> - if (match)
> - goto find_mux;
> - return NULL;
> - }
> -
> - /* Alternate Mode muxes */
> - nval = fwnode_property_count_u16(fwnode, "svid");
> - if (nval <= 0)
> - return NULL;
> -
> - val = kcalloc(nval, sizeof(*val), GFP_KERNEL);
> - if (!val)
> - return ERR_PTR(-ENOMEM);
> -
> - ret = fwnode_property_read_u16_array(fwnode, "svid", val, nval);
> - if (ret < 0) {
> - kfree(val);
> - return ERR_PTR(ret);
> - }
> -
> - for (i = 0; i < nval; i++) {
> - match = val[i] == desc->svid;
> - if (match) {
> - kfree(val);
> - goto find_mux;
> - }
> - }
> - kfree(val);
> - return NULL;
> + if (id)
> + return ERR_PTR(-ENOTSUPP);
>
> -find_mux:
> dev = class_find_device(&typec_mux_class, NULL, fwnode,
> mux_fwnode_match);
>
