From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lanttor Subject: uart issues on coldfire platform Date: Wed, 01 Jul 2009 10:20:48 +0800 Message-ID: <4A4AC800.3070901@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from az33egw02.freescale.net ([192.88.158.103]:53856 "EHLO az33egw02.freescale.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbZGACUm (ORCPT ); Tue, 30 Jun 2009 22:20:42 -0400 Received: from az33smr02.freescale.net (az33smr02.freescale.net [10.64.34.200]) by az33egw02.freescale.net (8.14.3/az33egw02) with ESMTP id n612KOT7026878 for ; Tue, 30 Jun 2009 19:20:37 -0700 (MST) Received: from zch01exm25.fsl.freescale.net (zch01exm25.ap.freescale.net [10.192.129.217]) by az33smr02.freescale.net (8.13.1/8.13.0) with ESMTP id n612KM7A017595 for ; Tue, 30 Jun 2009 21:20:23 -0500 (CDT) Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: linux-m68k@vger.kernel.org Hi, I find one issue of UART on my coldfire platforms (mcf54451evb board). I use the linux-2.6.29, and use drivers/serial/mcf.c and drivers/serial/serial_core.c as my uart driver source. Following is my test steps -- run command: cat /proc/interrupts two times contiguously. [root@freescale /]# cat /proc/interrupts M5445X *90: 5099 UART* M5445X 96: 3130 timer0 M5445X 99: 0 timer3 M5445X 100: 1569 fec(TXF) M5445X 101: 0 fec(TXB) M5445X 102: 0 fec(TXFIFO) M5445X 103: 0 fec(TXCR) M5445X 104: 3098 fec(RXF) M5445X 105: 0 fec(RXB) M5445X 106: 41 fec(MII) M5445X 107: 0 fec(LC) M5445X 108: 0 fec(HBERR) M5445X 109: 0 fec(GRA) M5445X 110: 0 fec(EBERR) M5445X 111: 0 fec(BABT) M5445X 112: 0 fec(BABR) [root@freescale /]# cat /proc/interrupts M5445X *90: 5714 UART* M5445X 96: 3700 timer0 M5445X 99: 1 timer3 M5445X 100: 1574 fec(TXF) M5445X 101: 0 fec(TXB) M5445X 102: 0 fec(TXFIFO) M5445X 103: 0 fec(TXCR) M5445X 104: 3108 fec(RXF) M5445X 105: 0 fec(RXB) M5445X 106: 47 fec(MII) M5445X 107: 0 fec(LC) M5445X 108: 0 fec(HBERR) M5445X 109: 0 fec(GRA) M5445X 110: 0 fec(EBERR) M5445X 111: 0 fec(BABT) M5445X 112: 0 fec(BABR) I find that the interrupts for above operation is 5714 - 5099 = 605 Is it normal? (my opinion it's too much) I test it on the mcf5329 board, it has the same-like result (even more 605). Actually I don't modify any code of mcf.c and serial_core.c, but I don't know why so much interrupts are occurred through one operation? Regards, Lanttor