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From: Wolfram Sang <wsa@the-dreams.de>
To: Muthu Mani <muth@cypress.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>,
	Lee Jones <lee.jones@linaro.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Alexandre Courbot <gnurou@gmail.com>,
	gregkh@linuxfoundation.org, Johan Hovold <johan@kernel.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-i2c@vger.kernel.org, linux-gpio@vger.kernel.org,
	Rajaram Regupathy <rera@cypress.com>
Subject: Re: [PATCH v4 2/3] i2c: add support for Cypress CYUSBS234 USB-I2C adapter
Date: Wed, 3 Dec 2014 12:07:55 +0100	[thread overview]
Message-ID: <20141203110755.GA1039@katana> (raw)
In-Reply-To: <1417241986-17841-1-git-send-email-muth@cypress.com>

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Hi,

thanks for this submission. Looks like an interesting device. However,
some very high level questions first:

> +/*
> + * It exposes sysfs entries under the i2c adapter for getting the i2c transfer
> + * status, reset i2c read/write module, get/set nak and stop bits.
> + */

Yes, I see that. Yet, I don't know why they are needed? The driver
should know when to send NAK/STOP. Why expose that to the user? And why
do we need a reset? Are there stability problems? What about unloading
the module? And what is the use case for reading the status?

> +       if (num > 1) {
> +               dev_err(&adapter->dev, "i2c_msg number is > 1\n");
> +               return -EIO;
> +       }

Ouch! Don't you have any repeated start option somewhere?

Thanks,

   Wolfram


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  reply	other threads:[~2014-12-03 11:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-29  6:19 [PATCH v4 2/3] i2c: add support for Cypress CYUSBS234 USB-I2C adapter Muthu Mani
2014-12-03 11:07 ` Wolfram Sang [this message]
2014-12-12 16:03   ` Muthu Mani
2014-12-13 12:14     ` Wolfram Sang
  -- strict thread matches above, loose matches on Subject: below --
2014-11-28 16:41 Muthu Mani

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