Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: rojay=codeaurora.org@mg.codeaurora.org
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
 format=flowed
Content-Transfer-Encoding: 8bit
Date:   Mon, 22 Mar 2021 16:32:27 +0530
From:   rojay@codeaurora.org
To:     Matthias Kaehlcke <mka@chromium.org>
Cc:     agross@kernel.org, bjorn.andersson@linaro.org,
        gregkh@linuxfoundation.org, robh+dt@kernel.org,
        linux-serial@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Rajendra Nayak <rnayak@codeaurora.org>,
        akashast@codeaurora.org, msavaliy@qti.qualcomm.com
Subject: Re: [PATCH V2 1/2] soc: qcom-geni-se: Cleanup the code to remove
 proxy votes
In-Reply-To: <YFOKQKlI3MjMouEA@google.com>
References: <20210318111009.30365-1-rojay@codeaurora.org>
 <20210318111009.30365-2-rojay@codeaurora.org> <YFOKQKlI3MjMouEA@google.com>
Message-ID: <91db2ee226ceb15a255bf7312a7216c1@codeaurora.org>
User-Agent: Roundcube Webmail/1.3.9
Precedence: bulk

On 2021-03-18 22:43, Matthias Kaehlcke wrote:
> On Thu, Mar 18, 2021 at 04:40:08PM +0530, Roja Rani Yarubandi wrote:
>> ICC core and platforms drivers supports sync_state feature, which
>> ensures that the default ICC BW votes from the bootloader is not
>> removed until all it's consumers are probes.
>> 
>> The proxy votes were needed in case other QUP child drivers
>> I2C, SPI probes before UART, they can turn off the QUP-CORE clock
>> which is shared resources for all QUP driver, this causes unclocked
>> access to HW from earlycon.
>> 
>> Given above support from ICC there is no longer need to maintain
>> proxy votes on QUP-CORE ICC node from QUP wrapper driver for early
>> console usecase, the default votes won't be removed until real
>> console is probed.
>> 
>> Signed-off-by: Roja Rani Yarubandi <rojay@codeaurora.org>
>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> 
> I suggest to mention that this is essentially a revert of commit
> 048eb908a1f2 ("soc: qcom-geni-se: Add interconnect support to fix
> earlycon crash"). This makes the life of reviewers easier and it's
> also good to have the reference in the git history.
> 

Ok.

> You could also mention commit 7d3b0b0d8184 ("interconnect: qcom:
> Use icc_sync_state") in the intro.
> 

Ok.

> I tried to test by first reproducing the original issue without
> 'sync_state' in the ICC, but wasn't successful, probably something
> changed in the boot/ICC timing in the meantime ¯\_(ツ)_/¯.
> 

Need to remove runtime auto suspend support from SPI/I2C as well, as it 
was
masking the issue by delaying to turn off the resources by 250ms.

> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>