Messages in this thread | | | Date | Tue, 21 Feb 2012 15:39:09 +0100 | From | Michael Thalmeier <> | Subject | Re: [PATCH] i.MX31: mxc-rnga: implement waiting for data in driver |
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On 2012-02-21 14:29, Fabio Estevam wrote:
> On Tue, Feb 21, 2012 at 10:13 AM, Michael Thalmeier > <michael.thalmeier@hale.at> wrote: > >> -static int mxc_rnga_data_present(struct hwrng *rng) >> +static int mxc_rnga_data_present(struct hwrng *rng, int wait) > > This looks good, but ... > >> { >> - int level; >> + int level, i; >> void __iomem *rng_base = (void __iomem *)rng->priv; >> >> - /* how many random numbers is in FIFO? [0-16] */ >> - level = ((__raw_readl(rng_base + RNGA_STATUS) & >> - RNGA_STATUS_LEVEL_MASK) >> 8); >> + for (i = 0; i < 20; i++) { > > Why the magic "20" here? > > It would be better to add a proper timeout mechanism instead, such as > time_after(jiffies, timeout) >
I am absolutely with you. The point is only that this is the behaviour of nearly all hw_random drivers, and I basically just copied it over into this driver.
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