From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jason J. Herne" Subject: [PATCH] Try #2: Use SCSI read/write(16) with >2TB drives Date: Wed, 14 Nov 2012 00:55:13 -0500 Message-ID: <1352872513-2424-1-git-send-email-hernejj@gmail.com> References: <50A2F12F.9060209 () redhat ! com> Return-path: Received: from mail-qc0-f174.google.com ([209.85.216.174]:39098 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756495Ab2KNFzT (ORCPT ); Wed, 14 Nov 2012 00:55:19 -0500 In-Reply-To: <50A2F12F.9060209 () redhat ! com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: linux-usb@vger.kernel.org, pbonzini@redhat.com, JBottomley@parallels.com, stern@rowland.harvard.edu, "Jason J. Herne" From: "Jason J. Herne" Force large capacity (> 2TB) drives to use READ/WRITE(16) instead of READ/WRITE(10). Some(most/all?) USB enclosures do not like READ(10) commands when a large capacity drive is installed. Signed-off-by: Jason J. Herne --- drivers/scsi/sd.c | 5 ++++- include/scsi/scsi_device.h | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 12f6fdf..9611d6b 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -887,7 +887,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq) SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff; SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff; SCpnt->cmnd[31] = (unsigned char) this_count & 0xff; - } else if (block > 0xffffffff) { + } else if (sdp->use_16_for_rw) { SCpnt->cmnd[0] += READ_16 - READ_6; SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0); SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0; @@ -2054,6 +2054,9 @@ got_data: } } + /* Use read/write(16) for > 2TB disks */ + sdp->use_16_for_rw = (sdkp->capacity > 0xffffffff); + /* Rescale capacity to 512-byte units */ if (sector_size == 4096) sdkp->capacity <<= 3; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 88fae8d..19ab8f1 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -135,6 +135,7 @@ struct scsi_device { * because we did a bus reset. */ unsigned use_10_for_rw:1; /* first try 10-byte read / write */ unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */ + unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */ unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */ unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */ unsigned skip_vpd_pages:1; /* do not read VPD pages */ -- 1.7.9.5