Am Montag, den 06.03.2017, 10:23 +0100 schrieb Johan Hovold: > [ +CC: Greg ] > > On Fri, Mar 03, 2017 at 07:29:02PM +0100, Oliver Neukum wrote: > > > > Am Donnerstag, den 02.03.2017, 12:51 +0100 schrieb Johan Hovold: > > > > > > This series refactors the endpoint sanity checks by allowing > > > subdrivers > > > to specify a minimum number of endpoints required per type and > > > letting > > > core verify this during probe. > > > > Hi, > > > > this is very good, but is it at the right place? I see nothing > > specific to serial drivers here. > > There are some usb-serial specifics here, most notably that the > constraints are specified per usb-serial type (driver) of which there > can be several per usb driver, and all with different ports counts > and > varying endpoint requirements. Yes, it would be wrong to see this as an attribute per driver. It needs to apply when you match. AFAICS every serial subdriver has a device table. Requirements need to go there. > As mentioned in the cover letter, a follow-on series will also use > the > descriptor arrays to allow subdrivers to manipulate the port-endpoint > mapping. We have a couple of driver for which a single endpoint pair > is > shared, but bulk-out resources are allocated per port anyway. To be > able > to get rid of some related hacks, the array sizes are therefore large > enough to express such mappings rather than having 15 elements each > (i.e. the maximum number of in or out endpoints). Yes, but could you explain how this is connected to filtering at probe time other than happening at probe time? > Also note that the constraints are verified only after the subdriver > probe > callback returns (but before calc_num_ports and attach) allowing the > drivers to change altsettings, download firmware, etc, before > verifying > that the endpoints required for normal operation are present. True, but again not specific to serial drivers. DVB-T will face the same issues. > Now, something similar to this could be added to USB core as well, > and I > believe Greg have been looking into that lately (as time permitted). > But > given the varying subdriver constraints, and the need for port- > endpoint > remapping, we'd still need these checks and features in USB serial. It looks like a duplicated effort to me and your code can already do most of the job. Just add a flag to check the requirements after probe() Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
