Messages in this thread Patch in this message | | | From | "Alexander V. Lukyanov" <> | Date | Sat, 18 Apr 1998 17:23:22 +0400 | Subject | Solution for hang in SMC setup (alpha/2.1.9[67]) |
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Recent kernels hung on my alpha PC164/433Mhz, just in SMC init. Don't know why, this started after I tried aic7xxx-5.0.12 in 2.1.95, continued in 2.1.96/97 which has that aic driver activated.
The strange thing was that the console messages did not indicate to a problem in aic driver, actually, the hang happened long before the driver init.
The last messages were: PCI: Probing PCI hardware. SMC FDC37C93X Ultra I/O Controller found @ 0x370
Then I tried to enable debug (define DEBUG) in drivers/pci/pci.c, and (magic!) the kernel booted ok. So I started to suspect compiler/binutils.
I turned off the debug in pci.c and started to insert debug messages into arch/alpha/kernel/smc37c93x.c and it showed that the hang happens on a particular outb. This seemed strange, and I started to suspect hardware.
The debug in pci.c caused several messages to be printed and I thought it can be the delay of printk's that prevented the hang. I inserted udelay(500) at top of SMC93x_Init and (magic again!) the kernel booted ok.
So the questions are: does anyone experience the hang on boot too? and does anybody know if pci bus scan can cause consequential io to hang? Maybe isa/pci bridge is unstable for some time after bus scan?
Ok, here is what I did: (maybe the delay is more appropriate in pci.c/pci_scan_bus)
--- smc37c93x.c.~1~ Tue Apr 7 14:45:04 1998 +++ smc37c93x.c Sat Apr 18 16:59:30 1998 @@ -12,6 +12,7 @@ #include <asm/hwrpb.h> #include <asm/io.h> #include <asm/segment.h> +#include <asm/delay.h>
#if 0 # define DBG_DEVS(args) printk args @@ -233,6 +234,8 @@ int __init SMC93x_Init(void) { unsigned long SMCUltraBase; + + udelay(500);
if ((SMCUltraBase = SMCDetectUltraIO()) != 0UL) { printk("SMC FDC37C93X Ultra I/O Controller found @ 0x%lx\n", Alexander.
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