cvs commit: src/sys/dev/ata atapi-cd.c atapi-cd.h
scottl at samsco.org
Fri Nov 16 09:54:30 PST 2007
Poul-Henning Kamp wrote:
> In message <473DCF61.6010107 at samsco.org>, Scott Long writes:
>>> What I've sortof talked phk into is that if I return the "right" error
>>> code in the "start" function, it will back off and not retry nor chatter.
>>> We still need the "access" function to return OK if HW present or we
>>> cannot send ioctl calls to an empty drive.
>> IMHO, overloading g_start just adds more cruft to the problem.
> The fundamental problem is that the CDROM ioctls don't distinguish
> between drive and media.
> In a nutshell: we are forced to let the open succeed, so the ioctl
> to close the tray can be issued, before we can get at the media.
> The problem with letting the open (aka g_access) succeed, is that
> the GEOM tasting starts.
> Redefining the ioctls is not a realistic option at this point, so
> the task is to find a workaround for the API-deficiency.
> What sos@ and I talked about is that we need to have an error return
> that says "The drive is here, but there is no media", to fail the
> tasting without GEOM reporting I/O errors on the console.
> The simplest way to do this, is probably to overload ENOENT or some
> other currently undefined errno for this effect.
But then why not have g_access be able to communicate the ability to
access the device independent from the ability to access the media?
Seems like both of these questions are "access" questions.
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