From mboxrd@z Thu Jan  1 00:00:00 1970
From: sbranden@broadcom.com (Scott Branden)
Date: Mon, 2 Mar 2015 11:41:05 -0800
Subject: [PATCH v2 2/2] hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver
In-Reply-To: <2555599.AxGoQ20pkj@wuerfel>
References: <1424888184-22180-3-git-send-email-sbranden@broadcom.com>
 <2093191.gujNGSl66k@wuerfel> <54F1E647.10106@broadcom.com>
 <2555599.AxGoQ20pkj@wuerfel>
Message-ID: <54F4BCD1.2020401@broadcom.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Arnd,

Thanks for the suggested change.

On 15-02-28 11:31 AM, Arnd Bergmann wrote:
> On Saturday 28 February 2015 08:01:11 Scott Branden wrote:
>>> The udelay(10) that the other drivers have seems about appropriate then,
>>> and we can independently think of a way to refine the interface.
>>> Please add a comment that explains the rate. Also, is there some kind
>>> of FIFO present in the hwrng device? If it can store close to 1ms work
>>> of data (1000 bits), you can just use an msleep(1) to wait for the
>>> pool to recover.
>> FIFO is 512 bits.  I will look as to whether we can live with 1/2
>> throughput.
>
> In that case, I think usleep_range(min(len * 8, 500), 500)) would be
> a good compromise: it waits at most until the fifo is full, but might
> return earlier if enough bits are available to fulfill the request.
OK, will change in next version.
>
> 	Arnd
>