Re: [PATCH] hwrng: bcm2835: fix oops when rng h/w is accessed during registration

[Herbert Xu]

On Thu, Apr 10, 2014 at 03:22:10PM -0400, Matt Porter wrote:
> Commit "d9e7972 hwrng: add randomness to system from rng sources"
> exposed a bug in the bcm2835-rng driver resulting in boot failure
> on Raspberry Pi due to the following oops:
> 
> [   28.261523] BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1]
> [   28.271058]
> [   28.275958] CPU: 0 PID: 1 Comm: swapper Not tainted 3.14.0+ #11
> [   28.285374] task: db480000 ti: db484000 task.ti: db484000
> [   28.294279] PC is at bcm2835_rng_read+0x28/0x48
> [   28.302276] LR is at hwrng_register+0x1a8/0x238
> .
> .
> .
> 
> The RNG h/w is not completely initialized and enabled before
> hwrng_register() is called and so the bcm2835_rng_read() fails.
> Fix this by making the warmup/enable writes before registering
> the RNG source with the hwrng core.
> 
> Signed-off-by: Matt Porter <mporter@xxxxxxxxxx>

Patch applied.  Thanks a lot!
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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