megaraid_sas: fix a small problem when reading state value from hw

When the driver reads state values from the hw it might happen that
different values are read in subsequent reads and this can cause problems,
this may lead to a timeout in this function and a non working adapter.

Cc: Adam Radford <aradford@gmail.com>
Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Shintaro Minemoto <fj3207hq@aa.jp.fujitsu.com>
Acked-by: Sumit Saxena <sumit.saxena@lsi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index d84d02c2aad9f53554362d0c11faa9d5b40af978..112799b131a93253d1b06170e2d7e1d5a1d998c2 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -3061,7 +3061,8 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
        u32 cur_state;
        u32 abs_state, curr_abs_state;
 
-       fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) & MFI_STATE_MASK;
+       abs_state = instance->instancet->read_fw_status_reg(instance->reg_set);
+       fw_state = abs_state & MFI_STATE_MASK;
 
        if (fw_state != MFI_STATE_READY)
                printk(KERN_INFO "megasas: Waiting for FW to come to ready"
@@ -3069,9 +3070,6 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
 
        while (fw_state != MFI_STATE_READY) {
 
-               abs_state =
-               instance->instancet->read_fw_status_reg(instance->reg_set);
-
                switch (fw_state) {
 
                case MFI_STATE_FAULT:
@@ -3223,10 +3221,8 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
                 * The cur_state should not last for more than max_wait secs
                 */
                for (i = 0; i < (max_wait * 1000); i++) {
-                       fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) &
-                                       MFI_STATE_MASK ;
-               curr_abs_state =
-               instance->instancet->read_fw_status_reg(instance->reg_set);
+                       curr_abs_state = instance->instancet->
+                               read_fw_status_reg(instance->reg_set);
 
                        if (abs_state == curr_abs_state) {
                                msleep(1);
@@ -3242,6 +3238,9 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
                               "in %d secs\n", fw_state, max_wait);
                        return -ENODEV;
                }
+
+               abs_state = curr_abs_state;
+               fw_state = curr_abs_state & MFI_STATE_MASK;
        }
        printk(KERN_INFO "megasas: FW now in Ready state\n");