Hey Alan, On 9/28/05, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote: > For PATA the requirements I'm aware of are > > - Interface for user to say "am about to swap" You mean something like "echo scsi-remove-single-device a b c d" > /proc/scsi/scsi? I guess the sysfs equivalent? > - Interface for user to say "have swapped" I suppose ditto. > - Must quiesce both master and slave before swap (or one per cable) The way I've written my infrastructure, this seems as if it'll just require another carefully placed hook function. > - Must reset to PIO_SLOW and then recompute modes for both devices > becuse it is possible that changing one changes the other timings This shouldn't be hard since I already do a similar reset by resetting udma_flags to a pre-init state. Probably in an if (!(ap->flags & ATA_FLAG_SATA)). > - The above is true for *unplug* too. A straight unplug may speed up the > other drive! > - Post hotswap need to reconfigure both drives as if from scratch Hmm, this seems far more complicated... basically during a swap operation, we have to shut down all I/O to the other drive on the cable (if there is one), if I read you correctly, and then reconfigure both drives once one is plugged in. >From what you're saying, it seems to me that the infrastructure I put forth will work as is, plus some if statements and extraneous PATA-only functions (and functionality like shutting down the other disk on the cable until the user calls the 'warm-swap complete' function'). How about this; I want this SATA hotswapping stuff to be tested, so I'll commit my patches for 'SATA only' for the time being. I'll stare at them for a while and then see what kind of PATA-specific if statements and hooks are necessary in the code? Luke - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
