Messages in this thread | | | From | Alexander Stein <> | Subject | Re: [PATCH] pch_dma: Fix channel locking | Date | Mon, 27 Jun 2011 16:22:52 +0200 |
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Hello,
On Friday 24 June 2011 07:28:12 Tomoya MORINAGA wrote: > Hi Alexander Stein > > I couldn't see the issue at all. > > (2011/06/23 16:42), Alexander Stein wrote: > > The close and open is actually needed (I had a separate application for > > that yesterday). > > Does the above mean that we must delete "close" processing from your > test program, right ? > (Modifying like this, I couldn't see the issue)
As you've written below, you used setserial to enable DMA mode. I used my own application for that using 2 ioctls.
> > If all is done without closing again, I get the following bug: > Does the above mean that executing your test program many times whose 2 > "close" are deleted , did you see the issue ?
The issue is only printed once. steps in short: * Enable DMA * Send 270 chars
> My steps like below > Boot Fedora14 > Install DMA driver > Install pch_uart driver > Enable DMA (setserial /dev/ttyPCH0 ^low_latency) > Modifying your test program > Delete 2 close() function. > Compile your test program. > Execute the tp. > Execute the tp. > Execute the tp. > I couldn't see any error message.
Ok. I have a 2.6.39 kernel with the following patches: pch_phub: Don't panic if dmi_get_system_info returns NULL drivers/tty/serial/pch_uart.c: don't oops if dmi_get_system_info returns NULL pch_uart: Add console support
I need these to get a booting board with console support on pch_uart. After boot (dma and pch_uart compiled into kernel), I do * setserial /dev/ttyPCH0 ^low_latency * ./raise_dma_fault <- Here I get the message
For the reference the used code for raise_dma_fault: #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/serial.h> int main(int argc, char *argv[]) { int fd; char buf[270];
fd = open ("/dev/ttyPCH0", O_RDWR); write (fd, buf, 270);
close (fd); return 0; }
Maybe you need to enable CONFIG_TRACE_IRQFLAGS and CONFIG_PROVE_LOCKING additionally to see the messages.
Regards, Alexander
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