Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754688AbYH3L5E (ORCPT ); Sat, 30 Aug 2008 07:57:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751426AbYH3L4w (ORCPT ); Sat, 30 Aug 2008 07:56:52 -0400 Received: from h155.mvista.com ([63.81.120.155]:31131 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751364AbYH3L4v (ORCPT ); Sat, 30 Aug 2008 07:56:51 -0400 Message-ID: <48B9357A.3040508@ru.mvista.com> Date: Sat, 30 Aug 2008 15:56:42 +0400 From: Sergei Shtylyov User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Elias Oltmanns Cc: Alan Cox , Andrew Morton , Bartlomiej Zolnierkiewicz , Jeff Garzik , Randy Dunlap , Tejun Heo , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] Introduce ata_id_has_unload() References: <87wshzplvk.fsf@denkblock.local> <20080829211345.4355.63012.stgit@denkblock.local> In-Reply-To: <20080829211345.4355.63012.stgit@denkblock.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1642 Lines: 53 Hello. Elias Oltmanns wrote: > Add a function to check an ATA device's id for head unload support as > specified in ATA-7. > > Signed-off-by: Elias Oltmanns > [...] > diff --git a/include/linux/ata.h b/include/linux/ata.h > index 80364b6..d9a94bd 100644 > --- a/include/linux/ata.h > +++ b/include/linux/ata.h > @@ -707,6 +707,23 @@ static inline int ata_id_has_dword_io(const u16 *id) > return 0; > } > > +static inline int ata_id_has_unload(const u16 *id) > +{ > + /* > + * ATA-7 specifies two places to indicate unload feature > + * support. Since I don't really understand the difference, > + * I'll just check both and only return zero if none of them > + * indicates otherwise. > If you read the comments to the words 82:84 and 85:87, they say that the former indicate the supported features, and the latter indicate the enabed features AND in case a feature can't be disabled, the latter words will have the corresponding bit set. So it should be sufficient to check only one word. > + */ > + if (ata_id_major_version(id) >= 7 > + && (((id[ATA_ID_CFSSE] & 0xC000) == 0x4000 > + && id[ATA_ID_CFSSE] & (1 << 13)) > + || ((id[ATA_ID_CSF_DEFAULT] & 0xC000) == 0x4000 > + && (id[ATA_ID_CSF_DEFAULT] & (1 << 13))))) > I think that it's preferrable to leave the operator on the same line with the first operand... WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/