linux-kernel - Re: [PATCH 6/6] soundwire: qcom: add support to new interrupts

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: <9707a9b9-1e10-e7bf-aea3-4da164c31ee1@linaro.org>
Date:   Mon, 1 Feb 2021 15:51:18 +0000
From:   Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        vkoul@...nel.org
Cc:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        sanyog.r.kale@...el.com, yung-chuan.liao@...ux.intel.com
Subject: Re: [PATCH 6/6] soundwire: qcom: add support to new interrupts



On 29/01/2021 19:38, Pierre-Louis Bossart wrote:
> 
> 
> On 1/29/21 11:32 AM, Srinivas Kandagatla wrote:
>> Add support to new interrupts and update irq routine in a way
>> to deal with multiple pending interrupts with in a single interrupt!
> 
> I can't parse the wording after 'update irq routine'.
> 

So, basically if we get an interrupt while processing previous one there 
is a chance that we might miss the new interrupt!

This was a bug with existing code, which only showed up with recent 
Headset Button Tests!

> 
>> +    swrm->reg_write(swrm, SWRM_INTERRUPT_CLEAR, intr_sts);
>> +    swrm->reg_write(swrm, SWRM_INTERRUPT_CLEAR, 0x0);
> 
> what does this second write 0x0 do? Usually interrupts are W1C, and you 
> didn't have this before.

Digging it bit more seems to be an HW work around for one of the issues, 
recommended by HW team. Will remove it from this patch and add it as 
separate one with more details!


--srini


>