From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trifle Menot Subject: serial performance Date: Fri, 12 Mar 2010 15:57:44 +0000 Message-ID: <201003121557.o2CFvlHK023131@beewyz.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-msdos-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-msdos@vger.kernel.org If I start dosemu -s with this: > $_ports = "fast range 0x3F8,0x3FF" > $_irqpassing = "4" A speed of 57600 looks fast, like it should be. But if I omit the direct hardware access, and try this: > $_com1 = "/dev/ttyS0 irq 4" 57600 still works, but looks much slower on the remote side of a null modem cable. Seems like I read where the code traps serial port writes and buffers data to /dev/ttyS0. Is the trapping causing the slowdown? Is there a cure? I don't want to use direct hardware access. I tested it that way, only to see how things work. I'm using the latest dosemu svn code. I first tried a 2.6.32 kernel on arch linux, but got a kernel panic, then tried a suse 2.6.11 kernel, and got these results. Both were i386 only, never x86_64. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php