diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index b65ce26ff72f..b3fd1f457639 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -8205,7 +8205,7 @@ struct flash_desc {
 	u32 size_mb;
 };
 
-static int get_flash_params(struct adapter *adap)
+static int t4_get_flash_params(struct adapter *adap)
 {
 	/* Table for non-Numonix supported flash parts.  Numonix parts are left
 	 * to the preexisting code.  All flash parts have 64KB sectors.
@@ -8214,40 +8214,136 @@ static int get_flash_params(struct adapter *adap)
 		{ 0x150201, 4 << 20 },       /* Spansion 4MB S25FL032P */
 	};
 
+	unsigned int part, manufacturer;
+	unsigned int density, size;
+	u32 flashid = 0;
 	int ret;
-	u32 info;
+
+	/* Issue a Read ID Command to the Flash part.  We decode supported
+	 * Flash parts and their sizes from this.  There's a newer Query
+	 * Command which can retrieve detailed geometry information but many
+	 * Flash parts don't support it.
+	 */
 
 	ret = sf1_write(adap, 1, 1, 0, SF_RD_ID);
 	if (!ret)
-		ret = sf1_read(adap, 3, 0, 1, &info);
+		ret = sf1_read(adap, 3, 0, 1, &flashid);
 	t4_write_reg(adap, SF_OP_A, 0);                    /* unlock SF */
 	if (ret)
 		return ret;
 
-	for (ret = 0; ret < ARRAY_SIZE(supported_flash); ++ret)
-		if (supported_flash[ret].vendor_and_model_id == info) {
-			adap->params.sf_size = supported_flash[ret].size_mb;
+	/* Check to see if it's one of our non-standard supported Flash parts.
+	 */
+	for (part = 0; part < ARRAY_SIZE(supported_flash); part++)
+		if (supported_flash[part].vendor_and_model_id == flashid) {
+			adap->params.sf_size = supported_flash[part].size_mb;
 			adap->params.sf_nsec =
 				adap->params.sf_size / SF_SEC_SIZE;
-			return 0;
+			goto found;
 		}
 
-	if ((info & 0xff) != 0x20)             /* not a Numonix flash */
-		return -EINVAL;
-	info >>= 16;                           /* log2 of size */
-	if (info >= 0x14 && info < 0x18)
-		adap->params.sf_nsec = 1 << (info - 16);
-	else if (info == 0x18)
-		adap->params.sf_nsec = 64;
-	else
-		return -EINVAL;
-	adap->params.sf_size = 1 << info;
-	adap->params.sf_fw_start =
-		t4_read_reg(adap, CIM_BOOT_CFG_A) & BOOTADDR_M;
+	/* Decode Flash part size.  The code below looks repetative with
+	 * common encodings, but that's not guaranteed in the JEDEC
+	 * specification for the Read JADEC ID command.  The only thing that
+	 * we're guaranteed by the JADEC specification is where the
+	 * Manufacturer ID is in the returned result.  After that each
+	 * Manufacturer ~could~ encode things completely differently.
+	 * Note, all Flash parts must have 64KB sectors.
+	 */
+	manufacturer = flashid & 0xff;
+	switch (manufacturer) {
+	case 0x20: { /* Micron/Numonix */
+		/* This Density -> Size decoding table is taken from Micron
+		 * Data Sheets.
+		 */
+		density = (flashid >> 16) & 0xff;
+		switch (density) {
+		case 0x14: /* 1MB */
+			size = 1 << 20;
+			break;
+		case 0x15: /* 2MB */
+			size = 1 << 21;
+			break;
+		case 0x16: /* 4MB */
+			size = 1 << 22;
+			break;
+		case 0x17: /* 8MB */
+			size = 1 << 23;
+			break;
+		case 0x18: /* 16MB */
+			size = 1 << 24;
+			break;
+		case 0x19: /* 32MB */
+			size = 1 << 25;
+			break;
+		case 0x20: /* 64MB */
+			size = 1 << 26;
+			break;
+		case 0x21: /* 128MB */
+			size = 1 << 27;
+			break;
+		case 0x22: /* 256MB */
+			size = 1 << 28;
+			break;
 
+		default:
+			dev_err(adap->pdev_dev, "Micron Flash Part has bad size, ID = %#x, Density code = %#x\n",
+				flashid, density);
+		return -EINVAL;
+		}
+		break;
+	}
+	case 0xc2: { /* Macronix */
+		/* This Density -> Size decoding table is taken from Macronix
+		 * Data Sheets.
+		 */
+		density = (flashid >> 16) & 0xff;
+		switch (density) {
+		case 0x17: /* 8MB */
+			size = 1 << 23;
+			break;
+		case 0x18: /* 16MB */
+			size = 1 << 24;
+			break;
+		default:
+			dev_err(adap->pdev_dev, "Macronix Flash Part has bad size, ID = %#x, Density code = %#x\n",
+				flashid, density);
+		return -EINVAL;
+		}
+	}
+	case 0xef: { /* Winbond */
+		/* This Density -> Size decoding table is taken from Winbond
+		 * Data Sheets.
+		 */
+		density = (flashid >> 16) & 0xff;
+		switch (density) {
+		case 0x17: /* 8MB */
+			size = 1 << 23;
+			break;
+		case 0x18: /* 16MB */
+			size = 1 << 24;
+			break;
+		default:
+			dev_err(adap->pdev_dev, "Winbond Flash Part has bad size, ID = %#x, Density code = %#x\n",
+				flashid, density);
+		return -EINVAL;
+		}
+		break;
+	}
+	default:
+		dev_err(adap->pdev_dev, "Unsupported Flash Part, ID = %#x\n",
+			flashid);
+		return -EINVAL;
+	}
+
+	/* Store decoded Flash size and fall through into vetting code. */
+	adap->params.sf_size = size;
+	adap->params.sf_nsec = size / SF_SEC_SIZE;
+
+found:
 	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);
+		dev_warn(adap->pdev_dev, "WARNING: Flash Part ID %#x, size %#x < %#x\n",
+			 flashid, adap->params.sf_size, FLASH_MIN_SIZE);
 	return 0;
 }
 
@@ -8285,7 +8381,7 @@ int t4_prep_adapter(struct adapter *adapter)
 	get_pci_mode(adapter, &adapter->params.pci);
 	pl_rev = REV_G(t4_read_reg(adapter, PL_REV_A));
 
-	ret = get_flash_params(adapter);
+	ret = t4_get_flash_params(adapter);
 	if (ret < 0) {
 		dev_err(adapter->pdev_dev, "error %d identifying flash\n", ret);
 		return ret;