linux-kernel - Re: [PATCH v3 net] net: phy: micrel: Dynamically control external clock of KSZ PHY

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: <20241210164308.6af97d00@kernel.org>
Date: Tue, 10 Dec 2024 16:43:08 -0800
From: Jakub Kicinski <kuba@...nel.org>
To: Wei Fang <wei.fang@....com>
Cc: "andrew@...n.ch" <andrew@...n.ch>, "hkallweit1@...il.com"
 <hkallweit1@...il.com>, "linux@...linux.org.uk" <linux@...linux.org.uk>,
 "davem@...emloft.net" <davem@...emloft.net>, "edumazet@...gle.com"
 <edumazet@...gle.com>, "pabeni@...hat.com" <pabeni@...hat.com>,
 "florian.fainelli@...adcom.com" <florian.fainelli@...adcom.com>,
 "heiko.stuebner@...rry.de" <heiko.stuebner@...rry.de>, "fank.li@....com"
 <fank.li@....com>, "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "imx@...ts.linux.dev" <imx@...ts.linux.dev>
Subject: Re: [PATCH v3 net] net: phy: micrel: Dynamically control external
 clock of KSZ PHY

On Tue, 10 Dec 2024 02:45:57 +0000 Wei Fang wrote:
> The simple fix could only fix the commit 985329462723 ("net: phy: micrel: use
> devm_clk_get_optional_enabled for the rmii-ref clock"), because as the commit
> message said some clock suppliers need to be enabled so that the driver can get
> the correct clock rate.
> 
> But the problem is that the simple fix cannot fix the 99ac4cbcc2a5 ("net: phy:
> micrel: allow usage of generic ethernet-phy clock"). The change is as follows,
> this change just enables the clock when the PHY driver probes. There are no
> other operations on the clock, such as obtaining the clock rate. So you still think
> a simple fix is good enough for net tree?

I may be missing something but if you don't need to disable the generic
clock you can put the disable into the if () block for rmii-ref ?

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 3ef508840674..8bbd2018f2a6 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -2214,6 +2214,8 @@ static int kszphy_probe(struct phy_device *phydev)
                                   rate);
                        return -EINVAL;
                }
+
+               clk_disable_unprepare(clk);
        } else if (!clk) {
                /* unnamed clock from the generic ethernet-phy binding */
                clk = devm_clk_get_optional_enabled(&phydev->mdio.dev, NULL);