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path: root/drivers/char/hw_random/intel-rng.c
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Diffstat (limited to 'drivers/char/hw_random/intel-rng.c')
-rw-r--r--drivers/char/hw_random/intel-rng.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/char/hw_random/intel-rng.c b/drivers/char/hw_random/intel-rng.c
index 753f46052b8..5cc651ef75e 100644
--- a/drivers/char/hw_random/intel-rng.c
+++ b/drivers/char/hw_random/intel-rng.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/stop_machine.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -162,11 +163,19 @@ static inline u8 hwstatus_set(void __iomem *mem,
return hwstatus_get(mem);
}
-static int intel_rng_data_present(struct hwrng *rng)
+static int intel_rng_data_present(struct hwrng *rng, int wait)
{
void __iomem *mem = (void __iomem *)rng->priv;
-
- return !!(readb(mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT);
+ int data, i;
+
+ for (i = 0; i < 20; i++) {
+ data = !!(readb(mem + INTEL_RNG_STATUS) &
+ INTEL_RNG_DATA_PRESENT);
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int intel_rng_data_read(struct hwrng *rng, u32 *data)