Hi AMrco, On Thursday 27 September 2007 16:44, Marco Tralli wrote: > I have random hangs on kernel boot or after few minutes on a NatSemi Geode > GX1 based PC-104 (from Advantech) using kernel 2.6.23-rc6. The system > locks, no way to use SysRq key, no usefull logs. > > No problems using kernel 2.6.21 series that I was using before with same > config options. > > I found that commenting out "geode_configure" call in > arch/i386/kernel/cpu/cyrix.c the problem is fixed. > > I guess recent changes to cyrix.c that replace macros setCx86/getCx86 with > inlined functions have now "activate" performance tricks in geode_configure > code that previously were "inactive" due to wrong macro espansion. So not > only "Suspend on Halt" function is enabled but also less or not documented > geode tricks (incrementor margin, fast fpu, write-back) now broken on some > GX1/GXm platform (maybe because of BIOS?)
Seems so. > I can further investigate on what exact geode_configure part cause my > hangs, but I suggest to make a config options to explicity enable Geode > performance tricks only if requested (maybe using CONFIG_MGEODEGX1) . That's my system: [EMAIL PROTECTED]:~ uname -a Linux morgan 2.6.22.8-cfs-v22-Igel316 #1 PREEMPT Wed Sep 26 15:09:46 CEST 2007 i586 unknown [EMAIL PROTECTED]:~ cat /proc/cpuinfo processor : 0 vendor_id : Geode by NSC cpu family : 5 model : 9 model name : Geode(TM) Integrated Processor by National Semi stepping : 2 cache size : 16 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu msr cx8 cmov mmx cxmmx bogomips : 99.94 clflush size : 32 It runs stable on 5 different GX1 systems. But I do not use a standard BIOS. I'm using LinuxBIOS instead. But I'm also using these patches. For documentation only: Index: linux-2.6.22/arch/i386/kernel/cpu/cyrix.c =================================================================== --- linux-2.6.22.orig/arch/i386/kernel/cpu/cyrix.c +++ linux-2.6.22/arch/i386/kernel/cpu/cyrix.c @@ -139,6 +139,23 @@ static void __cpuinit set_cx86_memwb(voi setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14 ); } +/* + * Setup the chipset specific Performance Control Incrementer + * + * The Performance Control Incrementer seems to be a delay line to control data + * setup time for DRAM access or it controls jitter. Its setting depends on CPU + * and DRAM clock (CPU and DRAM clock are coupled through a simple clock + * divider. For a 300 MHz CPU the divider is 3.0 to get a DRAM clock of 100MHz) + * There is an application note how to setup it: + * "AMD Geode GX1 Processor Memory Timings for Maximum Performance." + * Values for various CPUs: + * 1-0 for processor speed 200...266MHz + * 1-1 for processor speed 300 and 333MHz + * + * Note: If your system runs unstable after setting new values here, + * try with other values or leave the value as the BIOS setup it. + * The setting depends also on physical layout! + */ static void __cpuinit set_cx86_inc(void) { unsigned char ccr3; And here I'm using an incrementer value for my 300MHz CPU: Index: linux-2.6.22/arch/i386/kernel/cpu/cyrix.c =================================================================== --- linux-2.6.22.orig/arch/i386/kernel/cpu/cyrix.c +++ linux-2.6.22/arch/i386/kernel/cpu/cyrix.c @@ -169,7 +169,7 @@ static void __cpuinit set_cx86_inc(void) setCx86(CX86_PCR1, getCx86(CX86_PCR1) | 0x02); /* PCR0 -- Performance Control */ /* Incrementor Margin 10 */ - setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x04); + setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x05); /* 300MHz CPU */ setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ } This should be done at runtime in relation to the real CPU clock. Hope it helps Juergen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/