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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <7edc0445-c5d4-64a7-0261-f9db9b10158e@linaro.org>
Date:   Wed, 21 Sep 2022 10:25:31 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     "Pandey, Radhey Shyam" <radhey.shyam.pandey@....com>,
        "Gaddam, Sarath Babu Naidu" <sarath.babu.naidu.gaddam@....com>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "edumazet@...gle.com" <edumazet@...gle.com>,
        "kuba@...nel.org" <kuba@...nel.org>,
        "pabeni@...hat.com" <pabeni@...hat.com>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "krzysztof.kozlowski+dt@...aro.org" 
        <krzysztof.kozlowski+dt@...aro.org>,
        "linux@...linux.org.uk" <linux@...linux.org.uk>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Simek, Michal" <michal.simek@....com>,
        "Sarangi, Anirudha" <anirudha.sarangi@....com>,
        "Katakam, Harini" <harini.katakam@....com>,
        "git@...inx.com" <git@...inx.com>, "git (AMD-Xilinx)" <git@....com>
Subject: Re: [RFC V2 PATCH 2/3] dt-bindings: net: xilinx_axienet: Introduce
 dmaengine binding support

On 21/09/2022 10:23, Pandey, Radhey Shyam wrote:
>>>  required:
>>>    - compatible
>>>    - interrupts
>>>    - reg
>>>    - xlnx,rxmem
>>>    - phy-handle
>>> +  - dmas
>>> +  - dma-names
>>>
>>>  additionalProperties: false
>>>
>>> @@ -132,11 +137,13 @@ examples:
>>>      axi_ethernet_eth: ethernet@...00000 {
>>>        compatible = "xlnx,axi-ethernet-1.00.a";
>>>        interrupt-parent = <&microblaze_0_axi_intc>;
>>> -      interrupts = <2>, <0>, <1>;
>>> +      interrupts = <1>;
>>
>> This looks like an ABI break. How do you handle old DTS? Oh wait... you do
>> not handle it at all.
> 
> Yes, this is anticipated ABI break due to major changes in axiethernet
> driver while adopting to dmaengine framework. Same is highlighted
> in commit description - "DT changes are not backward compatible 
> due to major driver restructuring/cleanup done in adopting the 
> dmaengine framework". 
> 
> Some background - Factor out AXI DMA code into separate driver was
> a TODO item (mentioned in driver changelog) and is being done as 
> part of this series. The DMA code is removed from axiethernet driver 
> and ethernet driver now make use of dmaengine framework to 
> communicate with AXIDMA IP.
> 
> When DMA code is removed from axiethernet driver there is limitation
> to support legacy DMA resources binding. One option is to inform
> user to switch to new binding when old DTS is detected? (and at some
> point we have to make this transition and remove dma code).

If you keep ABI non-broken, such message is a good idea.

> Please let us know if there are any other alternative to consider?

You just cannot break ABI just because you want to refactor some code in
driver.


Best regards,
Krzysztof

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ