> According to Annex B of ATA/ATAPI-5, IDENTIFY should be issued to the > slave device first to ensure that it releases PDIAG- and then use the > cable detection result from the master device. As we IDENTIFY master > first right after reset, slave if present is driving PDIAG-, so the > master on IDENTIFY always thinks the capacitor is present and 40c limit > is always applied. I had to go read this and its news to me but nice to know what is going on. > So, considering #1 and #2, it might be best to just believe what the > controller (BIOS) says and not bother about device side detection. In The BIOS is run once at boot, on an x86 box, maybe only for some controllers. > What do you think? I think we need to do the identify first. We could actually tidy up a lot of duplicate driver code if there was a ->cable_detect() method, as many of them could use the standard ata error handler without hooks. Right now it is mostly hooked just to do cable type setup. There are far too many cases from non-x86 through to hotplug we can't trust any BIOS bits. Alan - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
