netdev - Re: [PATCH 2/3] net: qcom/emac: do not reset the EMAC during initialization

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: <b0bbdab5-7c3d-b02e-3e69-a0cb4e214ef2@codeaurora.org>
Date:   Fri, 23 Jun 2017 13:37:58 -0500
From:   Timur Tabi <timur@...eaurora.org>
To:     David Miller <davem@...emloft.net>
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH 2/3] net: qcom/emac: do not reset the EMAC during
 initialization

On 06/23/2017 01:00 PM, David Miller wrote:
> What if the boot loader or something else left the chip in
> a weird state?

We depend on the boot loader leaving the NIC in a very specific state 
already, otherwise the driver can't initialize the hardware.  The 
firmware has to pre-initialize the EMAC for us.

Not only that, but the driver was resetting the MAC *after* programming 
the clocks (on non-ACPI systems) and initializing both PHYs.

> I'm not applying this.
> 
> If it's correct, the explanation in this commit message need
> to be imporved.  The change must be better justified.

Since this is for ACPI systems, I could do this:

	if (!has_acpi_companion(&pdev->dev))
		emac_mac_reset(adpt);

But at the very least, the call should be moved to earlier in the function.

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.