linux-kernel - Re: [PATCH v3 16/22] firmware: arm_scmi: add arm

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: <CABb+yY1w358uw2EoeioAvZy06LTuOO0krGFFXoQSNAR5m5ANmQ@mail.gmail.com>
Date:   Fri, 6 Oct 2017 19:17:17 +0530
From:   Jassi Brar <jassisinghbrar@...il.com>
To:     Sudeep Holla <sudeep.holla@....com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        ALKML <linux-arm-kernel@...ts.infradead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>,
        Roy Franz <roy.franz@...ium.com>,
        Harb Abdulhamid <harba@...eaurora.org>,
        Nishanth Menon <nm@...com>, Loc Ho <lho@....com>,
        Alexey Klimov <alexey.klimov@....com>,
        Ryan Harkin <Ryan.Harkin@....com>
Subject: Re: [PATCH v3 16/22] firmware: arm_scmi: add arm_mhu specific mailbox interface

On Fri, Oct 6, 2017 at 7:02 PM, Sudeep Holla <sudeep.holla@....com> wrote:
>
>
> On 06/10/17 12:26, Jassi Brar wrote:
>> On Wed, Oct 4, 2017 at 5:06 PM, Arnd Bergmann <arnd@...db.de> wrote:
>>> On Thu, Sep 28, 2017 at 3:11 PM, Sudeep Holla <sudeep.holla@....com> wrote:
>>>> This patch adds ARM MHU specific mailbox interface for SCMI.
>>>>
>>>> Cc: Arnd Bergmann <arnd@...db.de>
>>>> Signed-off-by: Sudeep Holla <sudeep.holla@....com>
>>>
>>> This clearly needs an explanation why we need another driver.
>>>
>> Yes the patch needs explanation which is that we need a shim layer to
>> map SCMI requests onto what the underlying controller expects. The
>> alternative was to clone the controller driver (MHU now and others
>> later when their platforms support SCMI) and pretend SCMI is the only
>> client they are ever going to serve.
>>
>
> Again that's not the point, doorbell is more common feature and that can
> be supported. As SCMI expects doorbell feature in the specification, it
> just need to support that class of controllers.
>
NO.  All SCMI expects is SHMEM and a signal reaching the other end.
The signal mechanism need not necessarily be "doorbell".