mlx4_core: Workaround firmware bug in query dev cap

ConnectX firmware is supposed to report the number blue flame
registers per page as log2 of the value.  However, due to a firmware
bug, it reports actual number.  This patch works around this by
checking if the number of registers calculated fits within a page.  If
it does not, we use 8 registers per page.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/net/mlx4/fw.c b/drivers/net/mlx4/fw.c
index b68eee2414c208765849d0136dfb7cb0065f52ba..7a7e18ba278a829bebc488e091fc615e8aed5825 100644 (file)
--- a/drivers/net/mlx4/fw.c
+++ b/drivers/net/mlx4/fw.c
@@ -289,6 +289,10 @@ int mlx4_QUERY_DEV_CAP(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap)
                MLX4_GET(field, outbox, QUERY_DEV_CAP_LOG_BF_REG_SZ_OFFSET);
                dev_cap->bf_reg_size = 1 << (field & 0x1f);
                MLX4_GET(field, outbox, QUERY_DEV_CAP_LOG_MAX_BF_REGS_PER_PAGE_OFFSET);
+               if ((1 << (field & 0x3f)) > (PAGE_SIZE / dev_cap->bf_reg_size)) {
+                       mlx4_warn(dev, "firmware bug: log2 # of blue flame regs is invalid (%d), forcing 3\n", field & 0x1f);
+                       field = 3;
+               }
                dev_cap->bf_regs_per_page = 1 << (field & 0x3f);
                mlx4_dbg(dev, "BlueFlame available (reg size %d, regs/page %d)\n",
                         dev_cap->bf_reg_size, dev_cap->bf_regs_per_page);