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-rw-r--r--drivers/scsi/scsi.c37
1 files changed, 14 insertions, 23 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index c4bf99a842f3..d0911bc28663 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -586,31 +586,22 @@ static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa,
if ((buf[1] & 0x03) != 0x03)
return false;
- /* See SPC-6, one command format of REPORT SUPPORTED OPERATION CODES */
+ /*
+ * See SPC-6, One_command parameter data format for
+ * REPORT SUPPORTED OPERATION CODES. We have the following cases
+ * depending on rwcdlp (buf[0] & 0x01) value:
+ * - rwcdlp == 0: then cdlp indicates support for the A mode page when
+ * it is equal to 1 and for the B mode page when it is
+ * equal to 2.
+ * - rwcdlp == 1: then cdlp indicates support for the T2A mode page
+ * when it is equal to 1 and for the T2B mode page when
+ * it is equal to 2.
+ * Overall, to detect support for command duration limits, we only need
+ * to check that cdlp is 1 or 2.
+ */
cdlp = (buf[1] & 0x18) >> 3;
- if (buf[0] & 0x01) {
- /* rwcdlp == 1 */
- switch (cdlp) {
- case 0x01:
- /* T2A page */
- return true;
- case 0x02:
- /* T2B page */
- return true;
- }
- } else {
- /* rwcdlp == 0 */
- switch (cdlp) {
- case 0x01:
- /* A page */
- return true;
- case 0x02:
- /* B page */
- return true;
- }
- }
- return false;
+ return cdlp == 0x01 || cdlp == 0x02;
}
/**