[SCSI] stex: adjust default queue length

Firmware of new version may adjust default queue length. It is
backward compatible.

Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 92dbac03c2e5..a20cbd9d325a 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -78,6 +78,7 @@ enum {
 
         MU_MAX_DELAY_TIME                       = 240000,
         MU_HANDSHAKE_SIGNATURE                  = 0x55aaaa55,
+        MU_HANDSHAKE_SIGNATURE_HALF             = 0x5a5a0000,
         HMU_PARTNER_TYPE                        = 2,
 
         /* firmware returned values */
@@ -902,6 +903,7 @@ static int stex_handshake(struct st_hba *hba)
         void __iomem *base = hba->mmio_base;
         struct handshake_frame *h;
         dma_addr_t status_phys;
+        u32 data;
         int i;
 
         if (readl(base + OMR0) != MU_HANDSHAKE_SIGNATURE) {
@@ -923,6 +925,13 @@ static int stex_handshake(struct st_hba *hba)
 
         udelay(10);
 
+        data = readl(base + OMR1);
+        if ((data & 0xffff0000) == MU_HANDSHAKE_SIGNATURE_HALF) {
+                data &= 0x0000ffff;
+                if (hba->host->can_queue > data)
+                        hba->host->can_queue = data;
+        }
+
         h = (struct handshake_frame *)(hba->dma_mem + MU_REQ_BUFFER_SIZE);
         h->rb_phy = cpu_to_le32(hba->dma_handle);
         h->rb_phy_hi = cpu_to_le32((hba->dma_handle >> 16) >> 16);
@@ -1234,7 +1243,7 @@ stex_probe(struct pci_dev *pdev, const struct pci_device_id *id)
         if (err)
                 goto out_free_irq;
 
-        err = scsi_init_shared_tag_map(host, ST_CAN_QUEUE);
+        err = scsi_init_shared_tag_map(host, host->can_queue);
         if (err) {
                 printk(KERN_ERR DRV_NAME "(%s): init shared queue failed\n",
                         pci_name(pdev));