Hugo Villeneuve <[email protected]> writes: > On Tue, 31 Mar 2009 21:31:13 -0700 > Kevin Hilman <[email protected]> wrote: > >> David Brownell <[email protected]> writes: >> >> > On Tuesday 31 March 2009, Mark A. Greer wrote: >> >> On Tue, Mar 31, 2009 at 01:43:41PM -0700, David Brownell wrote: >> >> > On Tuesday 31 March 2009, Mark A. Greer wrote: >> >> > > The serial infrastructure is pretty limited WRT this (I have >> >> > > same issue on da830 evm--I only want to use uart2). >> >> > >> >> > Couldn't you add some kind of "ignore this one" flag to that >> >> > infrastructure, and just have DaVinci use it? >> >> >> >> Yes and that's probably the right long-term solution. >> >> Problem is that code is used by almost everyone so who knows how >> >> long it'll take to get accepted. >> > >> > Accepted: should be easy with a sane patch. No existing >> > driver would be setting that new flag. >> > >> > Used widely: happens over time, like always. >> >> We ran into this same problem in OMAP too. The solution we ame up >> with is to just power-up all UARTs and an inactivity timer disables >> unused UART clocks. >> >> I tried a solution to this in the 8250 driver, but the bigger problem >> is that the 8250 driver is orphaned. Patches to add/fix features for >> the 8250 driver go largely ignored on the serial list. > > This all seems overly complicated to me. I don't like the idea of > registering a non-used serial port. I have no problem with having > ttyS0 and ttyS1 if I register UART0 and UART2. Symbolic > links can be used to make things more obvious like > /dev/mydevice -> /dev/ttyS0.
Yes, it is a bit complicated, but your solution leads to complications and confusion as well. Somebody has to manage symlinks when you decide you want to enable another UART for some other purpose. And symlink's don't help for kernel code using UARTs like the serial console or KGDB-over-serial etc. It also becomes confusing quickly when working accross different boards. Especially so if the board itself has the UARTs labeled, and your Linux kernel tells you it is UART0 and the board label says UART2. Kevin _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
