From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: [PATCH 05/07] sata_mv: workaround errata SATA#26 Date: Mon, 06 Apr 2009 15:24:57 -0400 Message-ID: <49DA5709.7060005@rtr.ca> References: <49DA2DFD.4010402@rtr.ca> <49DA2E33.4050704@rtr.ca> <49DA2E76.7000800@rtr.ca> <49DA566D.9040501@rtr.ca> <49DA56DE.3000200@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:33202 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753516AbZDFTY7 (ORCPT ); Mon, 6 Apr 2009 15:24:59 -0400 In-Reply-To: <49DA56DE.3000200@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik , IDE/ATA development list Cc: Saeed Bishara Workaround for errata SATA#26. Prevents accidently putting a drive to sleep when attempting COMRESET, by ORing 0xf000 with the values written to SCR_CONTROL. Signed-off-by: Mark Lord --- old/drivers/ata/sata_mv.c 2009-04-06 13:29:05.000000000 -0400 +++ new/drivers/ata/sata_mv.c 2009-04-06 14:20:53.000000000 -0400 @@ -1296,7 +1296,25 @@ unsigned int ofs = mv_scr_offset(sc_reg_in); if (ofs != 0xffffffffU) { - writelfl(val, mv_ap_base(link->ap) + ofs); + void __iomem *addr = mv_ap_base(link->ap) + ofs; + if (sc_reg_in == SCR_CONTROL) { + /* + * Workaround for 88SX60x1 FEr SATA#26: + * + * COMRESETs have to take care not to accidently + * put the drive to sleep when writing SCR_CONTROL. + * Setting bits 12..15 prevents this problem. + * + * So if we see an outbound COMMRESET, set those bits. + * Ditto for the followup write that clears the reset. + * + * The proprietary driver does this for + * all chip versions, and so do we. + */ + if ((val & 0xf) == 1 || (readl(addr) & 0xf) == 1) + val |= 0xf000; + } + writelfl(val, addr); return 0; } else return -EINVAL;