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| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2017-03-07 15:14:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-26 13:08:11 +0200 |
| commit | 48207bda7d7933a500a57af4671c72a0a22d5f63 (patch) | |
| tree | 54895d03f097dd21ec005f3671704d44ea6438ac | |
| parent | fd6fb9243d5632a592445d7584c9fffde62da44f (diff) | |
| download | linux-48207bda7d7933a500a57af4671c72a0a22d5f63.tar.gz linux-48207bda7d7933a500a57af4671c72a0a22d5f63.tar.bz2 linux-48207bda7d7933a500a57af4671c72a0a22d5f63.zip | |
hwrng: omap - write registers after enabling the clock
commit 45c2fdde01299b02a6e3225e848598a3c1e55539 upstream.
Commit 383212425c926 ("hwrng: omap - Add device variant for SafeXcel
IP-76 found in Armada 8K") added support for the SafeXcel IP-76 variant
of the IP. This modification included getting a reference and enabling a
clock. Unfortunately, this was done *after* writing to the
RNG_INTMASK_REG register. This generally works fine when the driver is
built-in because the clock might have been left enabled by the
bootloader, but fails short when the driver is built as a module: it
causes a system hang because a register is being accessed while the
clock is not enabled.
This commit fixes that by making the register access *after* enabling
the clock.
This issue was found by the kernelci.org testing effort.
Fixes: 383212425c926 ("hwrng: omap - Add device variant for SafeXcel IP-76 found in Armada 8K")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/char/hw_random/omap-rng.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c index 3ad86fdf954e..efa3747c1750 100644 --- a/drivers/char/hw_random/omap-rng.c +++ b/drivers/char/hw_random/omap-rng.c @@ -397,7 +397,6 @@ static int of_get_omap_rng_device_details(struct omap_rng_dev *priv, irq, err); return err; } - omap_rng_write(priv, RNG_INTMASK_REG, RNG_SHUTDOWN_OFLO_MASK); priv->clk = of_clk_get(pdev->dev.of_node, 0); if (IS_ERR(priv->clk) && PTR_ERR(priv->clk) == -EPROBE_DEFER) @@ -408,6 +407,8 @@ static int of_get_omap_rng_device_details(struct omap_rng_dev *priv, dev_err(&pdev->dev, "unable to enable the clk, " "err = %d\n", err); } + + omap_rng_write(priv, RNG_INTMASK_REG, RNG_SHUTDOWN_OFLO_MASK); } return 0; } |