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From: Chris Morgan <macroalpha82@gmail.com>
To: linux-wireless@vger.kernel.org
Cc: kvalo@kernel.org,
	pkshih@realtek.com,
	Chris Morgan <macromorgan@hotmail.com>
Subject: [PATCH] wifi: rtw88: Use random MAC when efuse MAC invalid
Date: Fri,  8 Dec 2023 09:07:39 -0600
Message-Id: <20231208150739.129753-1-macroalpha82@gmail.com>
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From: Chris Morgan <macromorgan@hotmail.com>

When the MAC address read from the efuse data is invalid, warn the
user and use a random MAC address instead.

On a device I am currently using (Anbernic RG-ARC) with a rtw8821cs
the efuse appears to be incompletely/improperly programmed. The MAC
address reads as ff:ff:ff:ff:ff:ff. When networkmanager attempts to
initiate a connection (and I haven't hard-coded a MAC address or
set it to random) it fails to establish a connection.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
---
 drivers/net/wireless/realtek/rtw88/main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index 4a33d2e47f33..6d22628129d0 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -2008,6 +2008,11 @@ static int rtw_chip_efuse_info_setup(struct rtw_dev *rtwdev)
 	efuse->ext_pa_5g = efuse->pa_type_5g & BIT(0) ? 1 : 0;
 	efuse->ext_lna_2g = efuse->lna_type_5g & BIT(3) ? 1 : 0;
 
+	if (!is_valid_ether_addr(efuse->addr)) {
+		eth_random_addr(efuse->addr);
+		dev_warn(rtwdev->dev, "efuse MAC invalid, using random\n");
+	}
+
 out_disable:
 	rtw_chip_efuse_disable(rtwdev);
 
-- 
2.34.1