linux-kernel - Re: [PATCH v8 01/11] firmware: arm_scmi: Add configurable polling mode for transports

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Message-ID: <20211221193852.pmb4nu43zzu6trqt@ti.com>
Date:   Wed, 22 Dec 2021 01:08:54 +0530
From:   Pratyush Yadav <p.yadav@...com>
To:     Cristian Marussi <cristian.marussi@....com>
CC:     <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <sudeep.holla@....com>,
        <james.quinlan@...adcom.com>, <Jonathan.Cameron@...wei.com>,
        <f.fainelli@...il.com>, <etienne.carriere@...aro.org>,
        <vincent.guittot@...aro.org>, <souvik.chakravarty@....com>
Subject: Re: [PATCH v8 01/11] firmware: arm_scmi: Add configurable polling
 mode for transports

Hi,

On 20/12/21 07:56PM, Cristian Marussi wrote:
> SCMI communications along TX channels can optionally be provided of a
> completion interrupt; when such interrupt is not available, command
> transactions should rely on polling, where the SCMI core takes care to
> repeatedly evaluate the transport-specific .poll_done() function, if
> available, to determine if and when a request was fully completed or
> timed out.
> 
> Such mechanism is already present and working on a single transfer base:
> SCMI protocols can indeed enable hdr.poll_completion on specific commands
> ahead of each transfer and cause that transaction to be handled with
> polling.
> 
> Introduce a couple of flags to be able to enforce such polling behaviour
> globally at will:
> 
>  - scmi_desc.force_polling: to statically switch the whole transport to
>    polling mode.
> 
>  - scmi_chan_info.no_completion_irq: to switch a single channel dynamically
>    to polling mode if, at runtime, is determined that no completion
>    interrupt was available for such channel.
> 
> Signed-off-by: Cristian Marussi <cristian.marussi@....com>

This patch breaks linux-next build for me with LLVM.

drivers/firmware/arm_scmi/driver.c:869:6: error: variable 'i_' is uninitialized when used within its own initialization [-Werror,-Wuninitialized]
        if (IS_POLLING_ENABLED(cinfo, info))
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/firmware/arm_scmi/driver.c:59:33: note: expanded from macro 'IS_POLLING_ENABLED'
                        IS_TRANSPORT_POLLING_CAPABLE(i_));              \
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
drivers/firmware/arm_scmi/driver.c:45:19: note: expanded from macro 'IS_TRANSPORT_POLLING_CAPABLE'
        typeof(__i) i_ = __i;                                           \
                    ~~   ^~~
1 error generated.

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.