Hi John, Andrew,
Can you check whether only the following change makes the problem go away. If yes, then it looks like a hardware issue. > hpet_writel(hpet_tick, HPET_T0_CMP); >+ hpet_writel(hpet_tick, HPET_T0_CMP); /* AK: why twice? */ > Thanks, Venki >-----Original Message----- >From: john stultz [mailto:[EMAIL PROTECTED] >Sent: Wednesday, February 02, 2005 6:05 PM >To: Pallipadi, Venkatesh >Cc: Andi Kleen; lkml; keith maanthey; Max Asbock; Chris McDermott >Subject: i386 HPET code > >Hey Venkatesh, > I've been looking into a bug where i386 2.6 kernels do >not boot on IBM >e325s if HPET_TIMER is enabled (hpet=disable works around the issue). >When running x86-64 kernels, the issue isn't seen. It appears >that after >the hpet is enabled, we stop receiving timer ticks. I've not played on >any other HPET enabled systems, nor have I looked at the HPET spec, so >I'm not sure if this is a hardware issue or not. > >The following patch, which uses the x86-64 code for >hpet_timer_stop_set_go() seems to fix the issue. > >Your thoughts? > >thanks >-john > > >===== arch/i386/kernel/time_hpet.c 1.10 vs edited ===== >--- 1.10/arch/i386/kernel/time_hpet.c 2004-11-02 06:40:42 -08:00 >+++ edited/arch/i386/kernel/time_hpet.c 2005-02-02 >17:59:27 -08:00 >@@ -64,29 +64,30 @@ > { > unsigned int cfg; > >- /* >- * Stop the timers and reset the main counter. >- */ >+/* >+ * Stop the timers and reset the main counter. >+ */ >+ > cfg = hpet_readl(HPET_CFG); >- cfg &= ~HPET_CFG_ENABLE; >+ cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY); > hpet_writel(cfg, HPET_CFG); > hpet_writel(0, HPET_COUNTER); > hpet_writel(0, HPET_COUNTER + 4); > >- /* >- * Set up timer 0, as periodic with first interrupt to happen at >- * hpet_tick, and period also hpet_tick. >- */ >- cfg = hpet_readl(HPET_T0_CFG); >- cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | >- HPET_TN_SETVAL | HPET_TN_32BIT; >- hpet_writel(cfg, HPET_T0_CFG); >- hpet_writel(tick, HPET_T0_CMP); >+/* >+ * Set up timer 0, as periodic with first interrupt to happen >at hpet_tick, >+ * and period also hpet_tick. >+ */ >+ >+ hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | >+ HPET_TN_32BIT, HPET_T0_CFG); >+ hpet_writel(hpet_tick, HPET_T0_CMP); >+ hpet_writel(hpet_tick, HPET_T0_CMP); /* AK: why twice? */ >+ >+/* >+ * Go! >+ */ > >- /* >- * Go! >- */ >- cfg = hpet_readl(HPET_CFG); > cfg |= HPET_CFG_ENABLE | HPET_CFG_LEGACY; > hpet_writel(cfg, HPET_CFG); > > > > - 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/
