Support Mac address pass through on Dell DS1000 dock

[Oliver Neukum <oneukum@suse.com>]

On Do, 2018-11-22 at 12:06 +0100, Frédéric Parrenin         wrote:
> Le 22/11/2018 à 11:22, Oliver Neukum a écrit :
> > On Mi, 2018-11-21 at 16:50 +0100, Frédéric Parrenin  wrote:
> > > which over rides the Mac on the dock. So, the answer is, "it's not an
> > > issue if the dock supports it, as the laptop BIOS is what is determining
> > > if it is supported".
> > > 
> > > So what is the truth?
> > 
> > For pass thru you must meet multiple conditions:
> > 
> > /* if this is not an RTL8153-AD, no eFuse mac passthru set,
> >   * or system doesn't provide valid _SB.AMAC this will be
> >   * be expected to non-zero
> >   */>
> > 
> > They can be manually verified. Do you need a debugging patch?
> 
> OK, let us try a debugging patch.

Here you go.
PLease enable dynamic debugging for the driver and ramp up
your logging level.

	Regards
		Oliver

From 3661ff35782f7b26df3204f4f7a18929e0c74ff7 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Thu, 22 Nov 2018 18:08:43 +0100
Subject: [PATCH] rtl8152: debugging for MAC pass-through

This adds debugging statements for failure cases in MAC
pass-through

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/usb/r8152.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 7345a2258ee4..3ed52806164c 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1168,19 +1168,28 @@ static int vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr *sa)
 
 	/* test for -AD variant of RTL8153 */
 	ocp_data = ocp_read_word(tp, MCU_TYPE_USB, USB_MISC_0);
-	if ((ocp_data & AD_MASK) != 0x1000)
+	if ((ocp_data & AD_MASK) != 0x1000) {
+		netif_dbg(tp, probe, tp->netdev,
+				"Not an AD type.\n");
 		return -ENODEV;
+	}
 
 	/* test for MAC address pass-through bit */
 	ocp_data = ocp_read_byte(tp, MCU_TYPE_USB, EFUSE);
-	if ((ocp_data & PASS_THRU_MASK) != 1)
+	if ((ocp_data & PASS_THRU_MASK) != 1) {
+		netif_dbg(tp, probe, tp->netdev,
+				"pass-through bit not set.\n");
 		return -ENODEV;
+	}
 
 	/* returns _AUXMAC_#AABBCCDDEEFF# */
 	status = acpi_evaluate_object(NULL, "\\_SB.AMAC", NULL, &buffer);
 	obj = (union acpi_object *)buffer.pointer;
-	if (!ACPI_SUCCESS(status))
+	if (!ACPI_SUCCESS(status)) {
+		netif_warn(tp, probe, tp->netdev,
+				"pass-through firmware failure.\n");
 		return -ENODEV;
+	}
 	if (obj->type != ACPI_TYPE_BUFFER || obj->string.length != 0x17) {
 		netif_warn(tp, probe, tp->netdev,
 			   "Invalid buffer for pass-thru MAC addr: (%d, %d)\n",
-- 
2.16.4