On Tue, 12 Feb 2008 12:45:35 -0600 James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 2008-02-12 at 10:22 -0800, Kristen Carlson Accardi wrote: > > I apologize for taking so long to review this patch. I obviously > > agree wholeheartedly with Luben. The problem I ran into while > > trying to design an enclosure management interface for the SATA > > devices is that there is all this vendor defined stuff. For > > example, for the AHCI LED protocol, the only "defined" LED is > > 'activity'. For LED2 and LED3 it is up to hardware vendors to > > define these. For SGPIO there's all kinds of ways for hw vendors > > to customize. I felt that it was going to be a maintainance > > nightmare to have to keep track of various vendors enclosure > > implementations in the ahci driver, and that it'd be better to just > > have user space libraries take care of that. Plus, that way a > > vendor doesn't have to get a patch into the kernel to get their new > > spiffy wizzy bang blinky lights working (think of how long it takes > > something to even get into a vendor kernel, which is what these > > guys care about...). So I'm still not sold on having an enclosure > > abstraction in the kernel - at least for the SATA controllers. > > Correct me if I'm wrong, but didn't the original AHCI enclosure patch > expose activity LEDs via sysfs? You are sort of wrong. we exposed a sysfs entry to enable sofware controlled activity LED, then the driver was responsible for turning it on and off. (blech, I know, but some vendors want this feature). > > I'm not saying there aren't a lot of non standard pieces that need to > be activated by direct commands or other user activated protocol. I > am saying there are a lot of standard pieces that we could do with > showing in a uniform manner. > > The pieces I think are absolutely standard are > > 1. Actual enclosure presence (is this device in an enclosure) > 2. Activity LED, this seems to be a feature of every enclosure. > > I also think the following are reasonably standard (based on the fact > that most enclosure standards recommend but don't require this): > > 3. Locate LED (for locating the device). Even if you only have an > activity LED, this is usually done by flashing the activity LED in a > well defined pattern. > 4. Fault. this is the least standardised of the lot, but does seem to > be present in about every enclosure implementation. > > All I've done is standardise these four pieces ... the services > actually take into account that it might not be possible to do > certain of these (like fault). > > James > > I understand what you are trying to do - I guess I just doubt the value you've added by doing this. I think that there's going to be so much customization that system vendors will want to add, that they are going to wind up adding a custom library regardless, so standardising those few things won't buy us anything. - To unsubscribe from this list: 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
