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SubjectRe: linux-2.3.24 and SERIAL_XMIT_SIZE
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Adam J. Richter wrote:
> In 2.3.24, <linux/tty.h> no longer pulls in <linux/serialP.h>.
> A bunch of serial drivers were relying on this to get a definition for

Adam, Thanks!

In the two drivers under my maintenance (specialix, sx), the buffer
size is actually assumed to be a page.

My drivers therefore really should have an

#define XMIT_BUF_SIZE PAGE_SIZE

at the top. The current definition wastes half a page when the page
size is 8192 (i.e. allocates it, but doesn't use it).... (And it'd
crash the system when the page size happens to be 2048 on some new
architecture....)

On the other hand, having too large an output buffer creates higher
latencies for some applications. Maybe maxing out at 4096 is a good
idea... #define XMIT_BUF_SIZE (min (PAGE_SIZE, 4096))

Adam, do you mind to "while you're at it" add this to the top of my
drivers instead of the #include ? Or do you want me to manage my own
drivers and push this to Linus myself? Or do you want me to submit
patches to you and allow me to delegate the "pushing Linus" to you?

Roger.

--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
"I didn't say it was your fault. I said I was going to blame it on you."

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