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From: Lanttor <lanttor.guo@freescale.com>
To: linux-m68k@vger.kernel.org
Subject: uart issues on coldfire platform
Date: Wed, 01 Jul 2009 10:20:48 +0800	[thread overview]
Message-ID: <4A4AC800.3070901@freescale.com> (raw)

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



             reply	other threads:[~2009-07-01  2:20 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-01  2:20 Lanttor [this message]
2009-07-01  6:30 ` uart issues on coldfire platform Lanttor
2009-07-02  0:40   ` [uClinux-dev] " Greg Ungerer
2009-07-02  2:21     ` Lanttor
2009-07-01 13:44 ` Matthew Lear

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