| Message ID | 4ACEA8FB.4060901@rtr.ca |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
Mark Lord wrote: > Bernie Innocenti wrote: >> >> I want to try reducing the frequency of the PCI-X bus, but the BIOS does >> not seem to provide a setting for it. Is there another way? > .. > > Nothing that's easy. .. Adding to that: there is a register on the chip, which software could use to override the normal auto-detected PCI mode (bus speed) for the chip. This could be used to, say, select 100Mhz or 66Mhz, or even 33Mhz operation. BUT.. the register is autodetected from the bus at power-on, and so if software wants to override that (by rewriting the reg), it will also need to reset the PCI bus afterward. Which requires knowing how to reset a PCI bridge, something I don't know about. Cheers -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- 2.6.31/drivers/ata/sata_mv.c.orig 2009-08-21 22:16:05.000000000 -0400 +++ linux/drivers/ata/sata_mv.c 2009-10-08 23:05:37.392203506 -0400 @@ -3738,6 +3738,12 @@ hp_flags |= MV_HP_ERRATA_60X1B2; break; case 0x9: + { + struct mv_host_priv *hpriv = host->private_data; + void __iomem *mmio = hpriv->base; + printk(KERN_INFO "sata_mv: pcix_mode=%d\n", mv_in_pcix_mode(host)); + printk(KERN_INFO "sata_mv: MV_PCI_COMMAND=%08x\n", readl(mmio + MV_PCI_COMMAND); + } hp_flags |= MV_HP_ERRATA_60X1C0; break; default: