linux-kernel - Re: [PATCH net] net: mdio: mdio-bcm-unimac: Correct rate fallback logic

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <9c10c78b-3818-4b97-8d10-bc038ec97947@broadcom.com>
Date: Tue, 29 Jul 2025 15:22:57 -0700
From: Florian Fainelli <florian.fainelli@...adcom.com>
To: Andrew Lunn <andrew@...n.ch>,
 Florian Fainelli <florian.fainelli@...adcom.com>
Cc: netdev@...r.kernel.org, Doug Berger <opendmb@...il.com>,
 Broadcom internal kernel review list
 <bcm-kernel-feedback-list@...adcom.com>,
 Heiner Kallweit <hkallweit1@...il.com>, Russell King
 <linux@...linux.org.uk>, "David S. Miller" <davem@...emloft.net>,
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Jacob Keller <jacob.e.keller@...el.com>,
 open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net] net: mdio: mdio-bcm-unimac: Correct rate fallback
 logic

On 7/29/25 15:20, Andrew Lunn wrote:
> On Tue, Jul 29, 2025 at 02:31:48PM -0700, Florian Fainelli wrote:
>> In case the rate for the parent clock is zero,
> 
> Is there a legitimate reason the parent clock would be zero?

Yes there is, the parent clock might be a gated clock that aggregates 
multiple sub-clocks and therefore has multiple "parents" technically. 
Because it has multiple parents, we can't really return a particular 
rate (clock provider is SCMI/firmware).

> 
> I can understand an optional clock being missing, but it seems odd
> that a clock is available, but it is ticking at 0Hz?
> 
> Maybe for this case, a warning should be issued to indicate something
> odd is going on?
> 
> 	Andrew
> 

-- 
Florian