Re: [SCSI] fix media change events for polled devices

From: Jeff Garzik
Date: Fri Mar 21 2008 - 16:36:55 EST


James Bottomley wrote:
On Fri, 2008-03-21 at 13:12 -0400, Jeff Garzik wrote:
Linux Kernel Mailing List wrote:
[SCSI] fix media change events for polled devices
Commit:
a341cd0f (SCSI: add asynchronous event notification API)
breaks:
285e9670 (sr,sd: send media state change modification events)
by introducing an event filter, which is removed here, to make
events, we are depending on, happen again.

By simply reading the code history, it is trivial to verify that this description is false:

Commit 285e9670 depends on a341cd0f, so by definition it is 285e9670 -- or rather the incomplete update of your original patch that resulted in 285e9670 -- that is broken.

Since commit 285e9670 is broken, you fixed the wrong thing.

Furthermore, you broke a userspace interface that was introduced by a341cd0f, by removing the event filter controlled by userspace.

Did anyone bother to read any code at all?

Yes, I did. The userspace interface has never worked as a writeable
attribute because it's read only (as Kay has pointed out several times).
Based on that, I just #if'd out the filter code to get polled media
events working again.

It has a show attribute and was obviously intended as a writable interface (and I should know, I wrote it).


The filter can be put back with a better discriminator for 2.6.26

When 285e9670 was updated for the scsi_evt_* interface, it should have initialized the supported_events mask.

That would break HAL ... it's using the presence of the media_event flag
in the variable to indicate it doesn't need to poll. We need two flags,
one for polling and one for AN.

Oh for pete's sake. How hard is it to create a second bit _and_ keep the existing AN featureset working?

_YOU_ are the one that broke this stuff in the first place, can you please take two seconds to fix it without breaking other stuff?

Jeff



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