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Subject: Re: [PATCH v9 6/9] i3c: master: Add driver for Cadence IP
To:     Boris Brezillon <boris.brezillon@bootlin.com>,
        Wolfram Sang <wsa@the-dreams.de>, <linux-i2c@vger.kernel.org>,
        Jonathan Corbet <corbet@lwn.net>, <linux-doc@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arnd Bergmann <arnd@arndb.de>
CC:     Przemyslaw Sroka <psroka@cadence.com>,
        Arkadiusz Golec <agolec@cadence.com>,
        Alan Douglas <adouglas@cadence.com>,
        Bartosz Folta <bfolta@cadence.com>,
        Damian Kos <dkos@cadence.com>,
        Alicja Jurasik-Urbaniak <alicja@cadence.com>,
        Cyprian Wronka <cwronka@cadence.com>,
        Suresh Punnoose <sureshp@cadence.com>,
        Rafal Ciepiela <rafalc@cadence.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Nishanth Menon <nm@ti.com>, Rob Herring <robh+dt@kernel.org>,
        Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Vitor Soares <Vitor.Soares@synopsys.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Xiang Lin <Xiang.Lin@synaptics.com>,
        <linux-gpio@vger.kernel.org>, Sekhar Nori <nsekhar@ti.com>,
        Przemyslaw Gaj <pgaj@cadence.com>,
        Peter Rosin <peda@axentia.se>,
        Mike Shettel <mshettel@codeaurora.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Joe Perches <joe@perches.com>
References: <20181022133404.2061-1-boris.brezillon@bootlin.com>
 <20181022133404.2061-7-boris.brezillon@bootlin.com>
 <20181024202048.7e3534f7@bbrezillon>
From:   Grygorii Strashko <grygorii.strashko@ti.com>
Message-ID: <99a506e3-d9d5-0d3e-26e1-031447c14857@ti.com>
Date:   Wed, 24 Oct 2018 15:25:17 -0500
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On 10/24/18 1:20 PM, Boris Brezillon wrote:
> Hi Arnd,
> 
> On Mon, 22 Oct 2018 15:34:01 +0200
> Boris Brezillon <boris.brezillon@bootlin.com> wrote:
> 
> 
>> +
>> +static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
>> +					    u8 *bytes, int nbytes)
>> +{
>> +	readsl(master->regs + RX_FIFO, bytes, nbytes / 4);
> 
> Vitor reported a problem with readsl(): this function expects the 2nd
> argument to be aligned on 32-bit, which is not guaranteed here. Unless
> you see a better solution, I'll switch back to a loop doing:
> 
> 	for (i = 0; i < nbytes; i += 4) {
> 		u32 tmp = __raw_readl(...);

Pls, do not use __raw io.

> 		memcpy(bytes + i, &tmp,
> 		       nbytes - i  > 4 ? 4 : nbytes - i);
> 	}
> 
>> +	if (nbytes & 3) {
>> +		u32 tmp;
>> +
>> +		readsl(master->regs + RX_FIFO, &tmp, 1);
>> +		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
>> +	}
>> +}
> 
> Regards,
> 
> Boris
> 

-- 
regards,
-grygorii