On Sunday 27 December 2020 18:42:19 Andy Shevchenko wrote:
On Sun, Dec 27, 2020 at 6:35 PM Pali Rohár pali@kernel.org wrote:
On Sunday 27 December 2020 18:28:25 Andy Shevchenko wrote:
On Sun, Nov 29, 2020 at 6:53 PM Pali Rohár pali@kernel.org wrote:
Now when usbtty serial console is fixed in U-Boot enable it for Nokia RX-51 board by default.
CONFIG_CONSOLE_MUX is already used and U-Boot console is available for all in/out devices. Therefore there is no need to have separate commands 'run sercon', 'run usbcon' and 'run vgacon', so remove them.
As space for U-Boot is limited to 256kB, disable some other unused options so CONFIG_USB_TTY can be enabled.
Nokia RX-51 does not have easily accessible UART serial console so the only option for easy debugging is to use device's keyboard+screen or this usbtty serial console over USB.
I think it's not a good idea to revive usbtty.
Well, but u-boot does not support anything else for Nokia N900. And main issues here are musb bugs which this patch series is fixing. For debugging is serial console (e.g. usbtty) needed.
I'm not against musb fixes, I'm against promoting usbtty. Why composite + f_serial can't be used for that?
Because nobody looked at it and invested time in it. usbtty was there for a long time and is working fine right now (with these musb patches).
I was recently playing around f_serial.c (I can send you the half baked stuff, which by a lot of twisted code in DWC3 driver is not working properly, actually almost not working) and I think that would be the right thing to do.
usbtty quite old, intrusive way of serial console via USB supported only by outdated hardware (like this Nokia N-900), while f_serial gotta work on better recent base. And I believe musb should be, if needed, patched to support composite devices.
So, kinda disagreement from my side as a summary on this. But disclaimer, I'm not a maintainer here, just my 2 cents.
-- With Best Regards, Andy Shevchenko