Messages in this thread Patch in this message | | | From | Milton Miller <> | Subject | Re: [PATCH 1/4] hvc_console: do not set low_latency | Date | Thu, 8 Jan 2009 07:25:14 -0600 |
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On Jan 8, 2009, at 6:36 AM, Alan Cox wrote:
>> v2.6.16-rc1 via 33f0f88f1c51ae5c2d593d26960c760ea154c2e2 >> [PATCH] TTY layer buffering revamp >> >> added this new api. > > No - tty_flip_buffer_push is from 2.1.66 and with the same constraints > from the day it was added. > Yes but wrappers were added and this this and many ohter drivers were converted to use them:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git; a=commitdiff;h=33f0f88f1c51ae5c2d593d26960c760ea154c2e2
And they were slightly buggy leading to the buggy workaround.
> >> Having the flag set for purely polled drivers will save delaying >> the work when receiving input for 1 jiffie. >> >> >> Index: work.git/drivers/char/hvc_console.c >> =================================================================== >> --- work.git.orig/drivers/char/hvc_console.c 2009-01-08 >> 03:01:24.000000000 -0600 >> +++ work.git/drivers/char/hvc_console.c 2009-01-08 03:01:51.000000000 >> -0600 >> @@ -318,7 +318,8 @@ static int hvc_open(struct tty_struct *t >> } /* else count == 0 */ >> >> tty->driver_data = hp; >> - tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */ >> + if (!hp->irq_requested) >> + tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */ >> >> hp->tty = tty; > > Looks good to me
Thanks, I guess that is an Ack?
milton
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