From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4AF638DD2; Mon, 11 Mar 2024 10:45:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.249 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710153910; cv=none; b=erS+JJsjgKvMV6IKBzwqFPLxF4WxIfDy67ft1cEJ14ugThNotzrEgmzv8H/ppoQkUKKwl6lLuTEziZVkF1yszsnEZwhEETEHO6Re0O4PSY6n82aw0Drio2zZjTsG6JAgAPCZhAwvvXulQcnb9cqCVpdTKsXb10L/JOL57ZUGWME= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710153910; c=relaxed/simple; bh=+sxHONNnx1hFuxK0YIAbVsDwlEeH+igDtPPWM75FSv4=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=BFPUNGZmw6t0ICYdgYH/9TqOjoDrZAmY4uqeNSA20oOfndeBzIMlHuK1Rg5KPZUN2590axFouflHR12AX5NS6+HnFOliCQPOJt2ZKuVMUtCVcxWP7rGmwSUDr6st/JEcxGVYJrN3IdXpzG1uSbsAM2Hd8TQDP2A84ulWYr6G2gg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=hyt+S1xV; arc=none smtp.client-ip=198.47.23.249 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="hyt+S1xV" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 42BAiruH107557; Mon, 11 Mar 2024 05:44:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1710153893; bh=brk8hEUtZhRYQimGd+K1WoJ4/pWrBZiyIAP9nhQEREs=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=hyt+S1xVq5Aa03sAcOxLAYUTmzaRTG91NigalPACIk2CoYlzcA3vdQNQtQgbS9Jfx 73lEWYCDa/Y0xGf7by0MS0M2mW6ZkVY7rXCLUO5vT+68zy9X1lNpyIyGBBQWSLuchf 7K8GFf9kG6LK4f9D6TlDMN3rrOXURGXSNUAl5MAI= Received: from DFLE106.ent.ti.com (dfle106.ent.ti.com [10.64.6.27]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 42BAirPa113120 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 11 Mar 2024 05:44:53 -0500 Received: from DFLE103.ent.ti.com (10.64.6.24) by DFLE106.ent.ti.com (10.64.6.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Mon, 11 Mar 2024 05:44:52 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE103.ent.ti.com (10.64.6.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Mon, 11 Mar 2024 05:44:52 -0500 Received: from [172.24.227.220] (chintan-thinkstation-p360-tower.dhcp.ti.com [172.24.227.220]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 42BAikUT105135; Mon, 11 Mar 2024 05:44:47 -0500 Message-ID: <0512d57f-af22-4bd8-8266-33d943d7eb4a@ti.com> Date: Mon, 11 Mar 2024 16:14:46 +0530 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/6] arm64: dts: ti: k3-j784s4: Add alias to MCU CPSW2G Content-Language: en-US To: Andrew Davis , Peter Rosin , Greg Kroah-Hartman , Conor Dooley , Krzysztof Kozlowski , Rob Herring , Tero Kristo , Vignesh Raghavendra , Nishanth Menon CC: , , , , , , References: <20240131101441.1362409-1-c-vankar@ti.com> <20240131101441.1362409-3-c-vankar@ti.com> <469a7f15-0539-48e9-993c-5b9c638917e0@ti.com> From: Chintan Vankar In-Reply-To: <469a7f15-0539-48e9-993c-5b9c638917e0@ti.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 On 31/01/24 21:06, Andrew Davis wrote: > On 1/31/24 4:14 AM, Chintan Vankar wrote: >> Add alias for the MCU CPSW2G port to enable Linux to fetch MAC Address >> for the port directly from U-Boot. > > Could you explain *how* this alias allows Linux to fetch a MAC > address from U-Boot? Sounds like we are doing something hacky here.. > Using "probe_daughtercards()" function U-Boot parses MAC addresses from EEPROM, then it internally calls "eth_env_set_enetaddr_by_index()" function which stores these MAC addresses into environment variables ethaddr, eth1addr, eth2addr and so on based on number of ports. U-Boot loads DTB during boot process, and it calls "fdt_fixup_ethernet()" function, which uses environment variables to update MAC addresses of ethernet ports as specified in the aliases section. > Why can't Linux fetch the MAC from efuses the same way U-Boot does, Linux can fetch the MAC address from efuses if "ti,syscon-efuse" property is enabled. > what happens if I don't use U-Boot to boot? If you don't use U-Boot to boot then the equivalent of "probe_daughtercards()" has to be implemented which is currently missing. > > Andrew > >> --- >>   arch/arm64/boot/dts/ti/k3-j784s4-evm.dts | 1 + >>   1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts >> b/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts >> index f34b92acc56d..b74f7d3025de 100644 >> --- a/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts >> +++ b/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts >> @@ -27,6 +27,7 @@ aliases { >>           mmc1 = &main_sdhci1; >>           i2c0 = &wkup_i2c0; >>           i2c3 = &main_i2c0; >> +        ethernet0 = &mcu_cpsw_port1; >>       }; >>       memory@80000000 {