lkml.org 
[lkml]   [2012]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/1] [RFC] uartclk from serial_core exposed to sysfs

> + /*
> + * Check value: baud_base has to be more than 9600
> + * and uartclock = baud_base * 16 .
> + */
> + if (val >= 153600)
> + state->uart_port->uartclk = val;
> +
> + mutex_unlock(&state->port.mutex);
> +
> + return count;

This breaks if for example the port is in use. Fixing that looks pretty
horrible as you need a valid tty pointer to stop and restart the pot.

It's also not calling the verfy method of the port as is expected.

At minimum I think you need to be able to do the same work
uart_get_info/uart_set_info perform and with the same checks on ->verify
etc.

I'm not 100% sure the drvdata on the tty_dev is clear to use. It does
seem to be in all the drivers I looked at. I'd rather however it pointed
to the tty_port that each tty device has (or very soon will be required
to have). You can still find the uart_foo structs from that but it means
we can do the dev_set_drvdata() in a consistent manner for all tty
devices in the kernel. That in turn means we can make some of the sysfs
valid the same way.

I want to have think about the setting side of it. Can you submit a
revised version that just allows the user to read the value this way but
does the drvdata setting etc and sysfs node create/delete.

I'll merge that and we can throw it over the parapet and see if anything
explodes.

To make the setting part work properly I think I need to sort out
uart_get_info/set_info so the core part of it can be called with kernel
space structures and the caller handling locks.

Alan


\
 
 \ /
  Last update: 2012-08-16 13:01    [W:0.471 / U:0.500 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site