Hi, Wouldn't the mere output on your console cause UART transmit interrupts for each character anyway ? (I can't imagine that the debug console is polled.. ? :-) The amount of console data would equate to 500+ TX interrupts, so AFAIK that would make sense. Unless the UART has a FIFO and the code *explicitly* empties the FIFO from within the serial ISR, which could be -say - 16 times less interrupts.
Do I have this right ? I wonder myself actually as I'm very new to uClinux, but I only work on ARM9 target for the moment. (which will be the subject of a question I would like to post, hence this reply is also a test if I _can_ post here already :-) Best Regards, Kris On Wed, 01 Jul 2009 14:30:54 +0800, Lanttor <lanttor....@freescale.com> wrote: >> 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. >> >> [r...@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) >> [r...@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 >> >> >> >> > _______________________________________________ > uClinux-dev mailing list > uClinux-dev@uclinux.org > http://mailman.uclinux.org/mailman/listinfo/uclinux-dev > This message was resent by uclinux-dev@uclinux.org > To unsubscribe see: > http://mailman.uclinux.org/mailman/options/uclinux-dev _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
