[PARPORT] Re: patch-2.1.131-ac8-1284


Andrea Arcangeli (andrea@e-mind.com)
Mon, 14 Dec 1998 21:29:05 +0100 (CET)


On Mon, 14 Dec 1998, Tim Waugh wrote:

>> This patch will implement a policy where the ieee_ops lowlevel function
>> has to be called with a callback not null. This will improve performance
>> because ~always there' s a valid callback set.
>
>Not sure about this one either. The saving isn't exactly colossal. ;-)

I think it' s cleaner to have not to check for null every time, once it' s
been proposed also for the VFS and if I remeber well other parts of the
kernel use this policy just now...

>> I just included patch-2.1.131-ac8-1284 + the patches above in my arca-tree
>> to handle more testing from people on more hardware...
>
>Okay. Are you planning to merge your arca tree into 2.2 though?

The objective of arca patches is to allow people to try the tree I am
running that can contains good/needed or experimental eventually broken
code. Once I think that something is pretty important (and I have a bit of
time) I ask for inclusion.

>> Tim and what about things like tunelp -w now?
>
>Um. What does tunelp -w do? ;-)

It's used to set LP_WAIT(minor).

With the ieee1284 code it should change the udelay(1):

                unsigned char val = (PARPORT_STATUS_SELECT
                                     | PARPORT_STATUS_ERROR
                                     | PARPORT_STATUS_BUSY);

                if (current->need_resched)
                        schedule();

                /* Write the character to the data lines. */
                parport_write_data (port, *byte++);
                udelay (1);
                ^^^^^^^^ 1 -> LP_WAIT(minor)

                /* Is the peripheral ready yet? */
                if (!parport_wait_peripheral (port, mask, val))
                        /* Skip the loop */
                        goto ready;

Andrea Arcangeli

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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:18:54 EST