linux-kernel - Re: [PATCH 1/1] spi: pxa2xx: add driver enabling message

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Message-ID: <400467d8-19d6-1796-5fa9-cb5b37d61792@linux.intel.com>
Date:   Wed, 10 Apr 2019 11:29:30 +0300
From:   Jarkko Nikula <jarkko.nikula@...ux.intel.com>
To:     Flavio Suligoi <f.suligoi@...m.it>,
        Daniel Mack <daniel@...que.org>,
        Haojian Zhuang <haojian.zhuang@...il.com>,
        Robert Jarzmik <robert.jarzmik@...e.fr>,
        Mark Brown <broonie@...nel.org>
Cc:     "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-spi@...r.kernel.org" <linux-spi@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] spi: pxa2xx: add driver enabling message

On 4/10/19 11:13 AM, Flavio Suligoi wrote:
>> [    9.506895] pxa2xx-spi pxa2xx-spi.13: no DMA channels available,
>> using PIO
>> [    9.516770] pxa2xx-spi pxa2xx-spi.13: registered master spi2
>> [    9.518527] pxa2xx-spi pxa2xx-spi.13: PXA2xx SPI master controller
>> (PIO mode)
> 
> I have added this message because, using an x86 machine, the message:
> 
> "pxa2xx-spi pxa2xx-spi.13: registered master spi2"
> 
> doesn't appear in the kernel messages!
> 
Yeah, it needs CONFIG_SPI_DEBUG.

>> Actually this info message doesn't necessarily tell will the driver end
>> up using DMA for transfers. See pxa2xx_spi_can_dma() and
>> pxa2xx_spi_transfer_one().
>>
>> How about replacing "no DMA channels available, using PIO" and have
>> instead single info message telling is the DMA available or does the
>> driver use PIO only?
> 
> Ok, it's a good idea, to avoid to many similar messages.
> So I can simply remove the:
> 
> "no DMA channels available, using PIO"
> 
> and leave only the new:
> 
> " pxa2xx-spi pxa2xx-spi.13: PXA2xx SPI master controller (PIO mode)"
> 
Yes, something like that.

Now I remember, please also take into account driver is dual role since 
commit ec93cb6f827b ("spi: pxa2xx: Add slave mode support").

-- 
Jarkko