Date: Fri, 23 Jan 2004 15:01:59 +0100 (CET)
From: Pascal Schmidt <der.eremit@email.de>
To: Jens Axboe <axboe@suse.de>
cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] make ide-cd handle non-2kB sector sizes
In-Reply-To: <20040123093525.GP2734@suse.de>
Message-ID: <Pine.LNX.4.44.0401231456450.944-100000@neptune.local>
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On Fri, 23 Jan 2004, Jens Axboe wrote:

> It's a good first start, thanks for doing this. You really want to be
> storing this info in the queue, though, there's a hardsector size just
> for this very purpose. That way other layers know about the hardware
> sector size as well, not just ide-cd. And you get other things right for
> free as well, for instance ide_cdrom_prep_fs() needs a correct hardware
> block size or it will build wrong cdbs.

Hmmm. I'm doing

	blk_queue_hardsect_size(drive->queue, sectors_per_frame << 9);

inside of cdrom_read_toc, is that not enough? Or do you mean that
I should only store it in the queue and not also in cdrom_state_flags?

> Hmm, you made it a bit more confusing. It should read that writes must
> be hardware sector aligned. Something ala
> 
> 	if ((rq->nr_sectors << 9) & (sector_size - 1) ||
> 	    (rq->sector & ((sector_size >> 9) - 1)))
> 		problem

I'll change that.

> > -	set_capacity(drive->disk, toc->capacity * SECTORS_PER_FRAME);
> > +	set_capacity(drive->disk, toc->capacity * sectors_per_frame);
> > +
> > +	if (CDROM_STATE_FLAGS(drive)->sectors_per_frame != sectors_per_frame)
> > +		printk(KERN_INFO "%s: new hardware sector size %lu\n",
> > +			drive->name, sectors_per_frame << 9);
> 
> if you feel you must print this, then do it in the same line as the
> other cdrom info printed.

This happens on disc change, no other info is normally printed. But this
printk can probably go away, I just put it there for debugging.

-- 
Ciao,
Pascal

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