| Message ID | 1397157730-31161-1-git-send-email-mporter@linaro.org |
|---|---|
| State | New |
| Headers | show |
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@linaro.org> Patch applied. Thanks a lot!
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index 8c3b255..e900961 100644 --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -61,18 +61,18 @@ static int bcm2835_rng_probe(struct platform_device *pdev) } bcm2835_rng_ops.priv = (unsigned long)rng_base; + /* set warm-up count & enable */ + __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); + __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); + /* register driver */ err = hwrng_register(&bcm2835_rng_ops); if (err) { dev_err(dev, "hwrng registration failed\n"); iounmap(rng_base); - } else { + } else dev_info(dev, "hwrng registered\n"); - /* set warm-up count & enable */ - __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); - __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); - } return err; }
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@linaro.org> --- drivers/char/hw_random/bcm2835-rng.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)