Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753896Ab2FFMUl (ORCPT ); Wed, 6 Jun 2012 08:20:41 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:33494 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753781Ab2FFMUi (ORCPT ); Wed, 6 Jun 2012 08:20:38 -0400 From: Namjae Jeon To: James.Bottomley@HansenPartnership.com, gregkh@linuxfoundation.org, mdharm-usb@one-eyed-alien.net Cc: linux-usb@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Namjae Jeon , Namjae Jeon , Pankaj Kumar , Amit Sahrawat Subject: [PATCH 1/3] scsi: set to WCE if usb cache quirk is present. Date: Wed, 6 Jun 2012 08:20:24 -0400 Message-Id: <1338985224-9684-1-git-send-email-linkinjeon@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1931 Lines: 50 Make use of USB quirk method to identify such HDD while reading the cache status in sd_probe(). If cache quirk is present for the HDD, lets assume that cache is enabled and make WCE bit equal to 1. Signed-off-by: Namjae Jeon Signed-off-by: Pankaj Kumar Signed-off-by: Amit Sahrawat --- drivers/scsi/sd.c | 9 +++++++-- include/scsi/scsi_device.h | 1 + 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 6f0a4c6..33faf6d 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2259,8 +2259,13 @@ bad_sense: sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n"); defaults: - sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n"); - sdkp->WCE = 0; + if (sdp->wce_quirk) { + sdkp->WCE = 1; + sd_printk(KERN_NOTICE, sdkp, "Assuming drive cache write back\n"); + } else { + sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n"); + sdkp->WCE = 0; + } sdkp->RCD = 0; sdkp->DPOFUA = 0; } diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 6efb2e1..8be0247 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -152,6 +152,7 @@ struct scsi_device { unsigned no_read_disc_info:1; /* Avoid READ_DISC_INFO cmds */ unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */ unsigned is_visible:1; /* is the device visible in sysfs */ + unsigned wce_quirk:1; /* cache read page is not available */ DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */ struct list_head event_list; /* asserted events */ -- 1.7.9.5 -- 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/