[PATCH 1/6] scsi: storvsc: Rather than look for sets of specific protocol versions, make decisions based on ranges.

From: "K. Y. Srinivasan" <kys@microsoft.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
	devel@linuxdriverproject.org, ohering@suse.com,
	jbottomley@parallels.com, hch@infradead.org,
	linux-scsi@vger.kernel.org, apw@canonical.com,
	vkuznets@redhat.com, jasowang@redhat.com
Cc: "keith.mange@microsoft.com" <keith.mange@microsoft.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>
Subject: [PATCH 1/6] scsi: storvsc: Rather than look for sets of specific protocol versions, make decisions based on ranges.
Date: Fri, 29 May 2015 13:29:14 -0700	[thread overview]
Message-ID: <1432931359-14473-1-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1432931336-14434-1-git-send-email-kys@microsoft.com>

From: keith.mange@microsoft.com <keith.mange@microsoft.com>

Rather than look for sets of specific protocol versions,
make decisions based on ranges. This will be safer and require fewer changes
going forward as we add more storage protocol versions.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/storvsc_drv.c |   11 +++--------
 1 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 3c6584f..582f3b5 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -988,8 +988,7 @@ static int storvsc_channel_init(struct hv_device *device)
 	 * support multi-channel.
 	 */
 	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
-	if ((vmbus_proto_version != VERSION_WIN7) &&
-	   (vmbus_proto_version != VERSION_WS2008))  {
+	if (vmbus_proto_version >= VERSION_WIN8) {
 		if (vstor_packet->storage_channel_properties.flags &
 		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 			process_sub_channels = true;
@@ -1758,9 +1757,7 @@ static int storvsc_probe(struct hv_device *device,
 	 * set state to properly communicate with the host.
 	 */
 
-	switch (vmbus_proto_version) {
-	case VERSION_WS2008:
-	case VERSION_WIN7:
+	if (vmbus_proto_version < VERSION_WIN8) {
 		sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 		vmstor_current_major = VMSTOR_WIN7_MAJOR;
@@ -1768,8 +1765,7 @@ static int storvsc_probe(struct hv_device *device,
 		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
 		max_targets = STORVSC_IDE_MAX_TARGETS;
 		max_channels = STORVSC_IDE_MAX_CHANNELS;
-		break;
-	default:
+	} else {
 		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
 		vmscsi_size_delta = 0;
 		vmstor_current_major = VMSTOR_WIN8_MAJOR;
@@ -1783,7 +1779,6 @@ static int storvsc_probe(struct hv_device *device,
 		 * VCPUs in the guest.
 		 */
 		max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
-		break;
 	}
 
 	scsi_driver.can_queue = (max_outstanding_req_per_channel *
-- 
1.7.4.1

