linux-kernel - Re: [RFC PATCH 0/2] serial: 8250_dw: IO space + polling mode support

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]

Date:   Mon, 26 Feb 2018 10:45:46 +0000
From:   John Garry <john.garry@...wei.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        <gregkh@...uxfoundation.org>, <jslaby@...e.com>,
        <p.zabel@...gutronix.de>, <heiko@...ech.de>,
        <ed.blake@...drel.com>, <jhogan@...nel.org>
CC:     <linux-serial@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linuxarm@...wei.com>
Subject: Re: [RFC PATCH 0/2] serial: 8250_dw: IO space + polling mode support


Hi Andy,

>>>> We require it for a development board for our hip06 platform.
>>>
>>> Okay, and this particular platform uses Synopsys IP?
>>
>> As I see this uart is really a virtual 8250, so HW details like apb
>> clocks and the like are hidden, so may not be relevant.
>
> Good to know.
>
>> However I will check with the BMC team to know the specific details.
>
>>>>>>  for supporting an 8250-compatible UART with
>>>>>> the following profile/features:
>>>>>> - platform device
>>>>>> - polling mode (i.e. no interrupt support)
>>>>>> - ACPI FW
>>>>>
>>>>> Elaborate this one, please.
>>>>
>>>> So we need to define our own HID here, and cannot use PNP
>>>> compatible
>>>> CID
>>>> (like PNP0501) as we cannot use the 8250 PNP driver.
>>>
>>> Why not? What are the impediments?
>>>
>>
>> To support the host controller for this device, we will create an
>> MFD,
>> i.e. platform device, per slave device.
>
> There is no answer here...
>
>>>> This is related to the Hisi LPC ACPI support, where we would
>>>> create
>>>> an
>>>> MFD (i.e. platform device) for the UART.
>>>
>>> Why you can't do properly in ACPI?
>
> No answer here either.
>
> Sorry, but with this level of communication it's no go for the series.
>

Sorry if my answers did not tell you want you want to know.

My point was that the 8250_pnp driver would be used for a pnp_device, 
but we are creating a platform device for this UART slave so would 
require a platform device driver, that which 8250_dw.c is. But I will 
check on pnp device support.

Much appreciated,
John