cxgb4: Add warning msg when attaching to adapters which have FLASHes smaller than 2Mb

Based on original work by Casey Leedom <leedom@chelsio.com>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index 586a5f1..22d7581 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -3897,6 +3897,10 @@
 	adap->params.sf_size = 1 << info;
 	adap->params.sf_fw_start =
 		t4_read_reg(adap, CIM_BOOT_CFG) & BOOTADDR_MASK;
+
+	if (adap->params.sf_size < FLASH_MIN_SIZE)
+		dev_warn(adap->pdev_dev, "WARNING!!! FLASH size %#x < %#x!!!\n",
+			 adap->params.sf_size, FLASH_MIN_SIZE);
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
index 06fa583..6833a7b 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
@@ -206,6 +206,12 @@
 	FLASH_CFG_START = FLASH_START(FLASH_CFG_START_SEC),
 	FLASH_CFG_MAX_SIZE = FLASH_MAX_SIZE(FLASH_CFG_NSECS),
 
+	/* We don't support FLASH devices which can't support the full
+	 * standard set of sections which we need for normal
+	 * operations.
+	 */
+	FLASH_MIN_SIZE = FLASH_CFG_START + FLASH_CFG_MAX_SIZE,
+
 	FLASH_FPGA_CFG_START_SEC = 15,
 	FLASH_FPGA_CFG_START = FLASH_START(FLASH_FPGA_CFG_START_SEC),