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path: root/drivers/char/hw_random/amd-rng.c
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Diffstat (limited to 'drivers/char/hw_random/amd-rng.c')
-rw-r--r--drivers/char/hw_random/amd-rng.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c
index 556fd81fa81..c422e870dc5 100644
--- a/drivers/char/hw_random/amd-rng.c
+++ b/drivers/char/hw_random/amd-rng.c
@@ -28,6 +28,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -52,11 +53,18 @@ MODULE_DEVICE_TABLE(pci, pci_tbl);
static struct pci_dev *amd_pdev;
-static int amd_rng_data_present(struct hwrng *rng)
+static int amd_rng_data_present(struct hwrng *rng, int wait)
{
u32 pmbase = (u32)rng->priv;
+ int data, i;
- return !!(inl(pmbase + 0xF4) & 1);
+ for (i = 0; i < 20; i++) {
+ data = !!(inl(pmbase + 0xF4) & 1);
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int amd_rng_data_read(struct hwrng *rng, u32 *data)