netdev - Re: [PATCH] net: phy: Only resume phy if it is suspended

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: <c2ce6d12-fb5e-4067-aa7c-4f57f4eb4613@broadcom.com>
Date: Tue, 5 Dec 2023 16:12:41 -0800
From: Florian Fainelli <florian.fainelli@...adcom.com>
To: Justin Chen <justin.chen@...adcom.com>, Andrew Lunn <andrew@...n.ch>
Cc: netdev@...r.kernel.org, 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>, open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] net: phy: Only resume phy if it is suspended

On 12/5/23 16:10, Justin Chen wrote:
> 
> 
> On 12/5/23 4:03 PM, Andrew Lunn wrote:
>> On Tue, Dec 05, 2023 at 03:42:29PM -0800, Justin Chen wrote:
>>> Resuming the phy can take quite a bit of time. Lets only resume the
>>> phy if it is suspended.
>>
>> Humm...
>>
>> https://lore.kernel.org/netdev/6d45f4da-c45e-4d35-869f-85dd4ec37b31@lunn.ch/T/
>>
>> If Broadcom PHYs are slow to resume, maybe you should solve this in
>> the broadcom resume handler, read the status from the hardware and
>> only do the resume if the hardware is suspended.
>>
>>       Andrew
> 
> Right... Guess this won't work. It is odd that during resume we call 
> __phy_resume twice. Once from phy_resume() and another at phy_start(). 
> Let me rethink this. Thanks for the feedback.

This might be something for us to figure out on the driver side, I think 
historically I have always followed the pattern of doing:

phy_suspend()
phy_stop()

and

phy_resume()
phy_start()

because it used to be necessary to do that way back when...
-- 
Florian

Download attachment "smime.p7s" of type "application/pkcs7-signature" (4221 bytes)