Re: [linux-usb-devel] [PATCH] Airprime driver improvements to allow full speed EvDO transfers

Alan Cox
2006-06-30T11:58:19Z

Ar Gwe, 2006-06-30 am 14:51 +0400, ysgrifennodd Sergei Organov:
> In fact, according to Alan Cox answer, the first call is useless here at
> all, i.e., tty_buffer_request_room() is for subsequent
> tty_insert_flip_char() calls in a loop, not for
> tty_insert_flip_string(). tty_insert_flip_string() calls
> tty_buffer_request_room() itself, and does it in a loop in attempt to
> find as much memory as possible.

Yep. Think of it as a hint that "I'm about to stuff xyz bytes into
memory" to get best memory efficiency.

> tty_insert_flip_string() returns number of bytes it has actually
> inserted, but I don't believe one can do much if it returns less than
> has been requested as it means that we are out of kernel memory.

Yes. I've been wondering if we should log the failure case somewhere,
either as a tty-> object or printk.

Alan