linux-kernel - Re: [PATCH V3] PCI/ASPM: reconfigure ASPM following hotplug for POLICY

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] [day] [month] [year] [list]

Message-ID: <48b14a37-3b5c-e128-aa96-b924d05b7636@codeaurora.org>
Date:   Mon, 13 Mar 2017 17:06:46 -0400
From:   Sinan Kaya <okaya@...eaurora.org>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     linux-pci@...r.kernel.org, timur@...eaurora.org,
        linux-arm-msm@...r.kernel.org,
        Mayurkumar Patel <mayurkumar.patel@...el.com>,
        open list <linux-kernel@...r.kernel.org>,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH V3] PCI/ASPM: reconfigure ASPM following hotplug for
 POLICY_DEFAULT

Hi Bjorn,

On 3/9/2017 5:27 PM, Bjorn Helgaas wrote:
> This is an aspect of the ASPM design that I don't like:
> 
>   - pcie_aspm_init_link_state() is called on a *bridge* after we've
>     enumerated any devices below the bridge, and we allocate the
>     link_state.
> 
>   - pcie_aspm_exit_link_state() is called on an *endpoint*, and if
>     we're removing the last endpoint below a bridge, we release the
>     *parent's* link_state.

I just posted V4 a minute ago. I divided ASPM init into two so that the
ASPM registers are captured in device_add path. 

There is a section of the ASPM init code that needs to walk all the devices
under the bridge. 

This section of the code is not working in device_add path as the link list
for child devices has not been set up yet. 

Unless you tell me there is a better way to handle this, I don't see how
we can remove the call from scan_slot. 

After further review, I think I can split PATCH V4 3/3 into two. Before
diving into too much clean up, I wanted to get some feedback as it is
obvious from the messed up cover letter.

Sinan

-- 
Sinan Kaya
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.