On 25 August 2016 at 20:48, Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> wrote: > On 08/25/2016 04:30 PM, Alan Stern wrote: >> >> On Thu, 25 Aug 2016, Jacek Anaszewski wrote: >> >>> I'd see it as follows: >>> >>> #cat available_ports >>> #1-1 1-2 2-1 >>> >>> #echo "1-1" > new_port >>> >>> #cat observed_ports >>> #1-1 >>> >>> #echo "2-1" > new_port >>> >>> #cat observed_ports >>> #1-1 2-1 >>> >>> We've already had few discussions about the sysfs designs trying >>> to break the one-value-per-file rule for LED class device, and >>> there was always strong resistance against. >> >> >> This scheme has multiple values in both the available_ports and >> observed_ports files. :-( Not that I have any better suggestions... > > > Right, I forgot to add a note here, that this follows space > separated list pattern similarly as in case of triggers attribute. > Of course other suggestions are welcome. So ppl have doubts about multiple values in a single sysfs file (whatever we call it: "ports" or "observed_ports"). Greg clearly said: > sysfs is "one value per file", here you are listing a bunch of things in > one sysfs file. Please don't do that. What about my idea of using "ports" subdirectory and having each port as separated file inside that subdir? I think there are two ways of doing this: 1) Having "ports" subdir with 0x0000 chmod files, one per each port specified as observable In this solution we need "new_port" and "remove_port" that can be used for management of observable ports. I think Jacek wasn't happy with this chmod and he believes Greg meant R/W files. 2) Having "ports" subdir with RW files, one per each existing physical port In this situation we don't need "new_port" or "remove_port". If we want port to be observable we just do: echo 1 > 1-1 Implementing this solution needs reading more details from USB subsystem. Do you find any of solutions with "ports" subdir better than dealing with new-line/space separated values in a single sysfs file? -- Rafał -- 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
