From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 2/3] Add EVPD page 0x83 to sysfs Date: Thu, 06 Mar 2014 10:01:05 +0100 Message-ID: <53183951.7080805@suse.de> References: <1392286032-85036-1-git-send-email-hare@suse.de> <1392286032-85036-3-git-send-email-hare@suse.de> <20140228170131.GA31510@infradead.org> <5316D459.6070107@suse.de> <20140305194255.GA5607@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:49265 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751190AbaCFJBH (ORCPT ); Thu, 6 Mar 2014 04:01:07 -0500 In-Reply-To: <20140305194255.GA5607@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: James Bottomley , linux-scsi@vger.kernel.org, Jeremy Linton , Kay Sievers , Doug Gilbert , Kai Makisara On 03/05/2014 08:42 PM, Christoph Hellwig wrote: > On Wed, Mar 05, 2014 at 08:38:01AM +0100, Hannes Reinecke wrote: >>> Either way I think the call to query evpd 0 should be a separate >>> function, so even if we don't store the information it's abstracted= out. >>> >> Hmm. That would work if we were just asking for a single page; but >> when we're checking several pages (like 0x83 and 0x80) we'd need >> either to pass in a page array or querying page 0 several times. >> Neither of which is very appealing. >> >> However, specifying additional flags for the individual pages might >> work. I'll see what I can come up with. >=20 > Passing in a bitmask or flags seems useful. Even better storing it i= n the > scsi_device. Note that I expect the place that need to know the EVPD > patch to grow slowly but steadily over time. >=20 I am somewhat reluctant here. Adding separate flags like 'support_vpd_pg83' is a bit pointless, given that we might as well check for vpg_pg83. So the only 'proper' solution would be to add a bitmap of supported pages; however, this would be 256 bits =3D 32 bytes of additional space required for struct sdev. Which I'm a bit reluctant do to, as it'll be a sparse array in most cases, adding to quite some wasted space. Thoughts? Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html