Re: [PATCH] mt76: mt7615: do not advertise 5 GHz on first phy of MT7615D (DBDC)

From: Paul Fertser <fercerpav@gmail.com>
To: Simon Horman <simon.horman@corigine.com>
Cc: linux-wireless@vger.kernel.org, Felix Fietkau <nbd@nbd.name>,
	Lorenzo Bianconi <lorenzo@kernel.org>,
	Ryder Lee <ryder.lee@mediatek.com>,
	Shayne Chen <shayne.chen@mediatek.com>,
	Sean Wang <sean.wang@mediatek.com>, Kalle Valo <kvalo@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@collabora.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, Rani Hod <rani.hod@gmail.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH] mt76: mt7615: do not advertise 5 GHz on first phy of MT7615D (DBDC)
Date: Tue, 6 Jun 2023 12:12:51 +0300	[thread overview]
Message-ID: <ZH74kw4M15qjDbTz@home.paul.comp> (raw)
In-Reply-To: <ZH72YwgpywPNxbd2@corigine.com>

Hi Simon,

On Tue, Jun 06, 2023 at 11:03:31AM +0200, Simon Horman wrote:
> On Mon, Jun 05, 2023 at 10:34:07AM +0300, Paul Fertser wrote:
> > On DBDC devices the first (internal) phy is only capable of using
> > 2.4 GHz band, and the 5 GHz band is exposed via a separate phy object,
> > so avoid the false advertising.
> 
> Can I clarify that the second object won't hit the logic change
> below and thus be limited to 2GHz?

The second object (external 5 GHz phy) doesn't have an EEPROM of its
own, and is created explicitly with just this band enabled:

https://elixir.bootlin.com/linux/latest/source/drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c#L104
https://elixir.bootlin.com/linux/latest/source/drivers/net/wireless/mediatek/mt76/mt7615/init.c#L573

So it won't hit the logic change and it will be limited to 5 GHz.

-- 
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