Revert "hwrng: bcm2835 - sleep more intelligently"

This reverts commit 6a825ed68f75bd768e31110ba825b75c5c09cf2d.

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index 84c964b..d31ef43 100644 (file)
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -13,7 +13,6 @@
 #include <linux/printk.h>
 #include <linux/clk.h>
 #include <linux/reset.h>
-#include <linux/delay.h>
 
 #define RNG_CTRL       0x0
 #define RNG_STATUS     0x4
@@ -28,9 +27,6 @@
 
 #define RNG_INT_OFF    0x1
 
-#define RNG_FIFO_WORDS 4
-#define RNG_US_PER_WORD        34 /* Tuned for throughput */
-
 struct bcm2835_rng_priv {
        struct hwrng rng;
        void __iomem *base;
@@ -67,23 +63,19 @@ static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val,
 static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
                               bool wait)
 {
-       u32 retries = 1000000/(RNG_FIFO_WORDS * RNG_US_PER_WORD);
        struct bcm2835_rng_priv *priv = to_rng_priv(rng);
        u32 max_words = max / sizeof(u32);
        u32 num_words, count;
 
-       num_words = rng_readl(priv, RNG_STATUS) >> 24;
-
-       while (!num_words) {
-               if (!wait || !retries)
+       while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) {
+               if (!wait)
                        return 0;
-               retries--;
-               usleep_range((u32)RNG_US_PER_WORD,
-                            (u32)RNG_US_PER_WORD * RNG_FIFO_WORDS);
-               num_words = rng_readl(priv, RNG_STATUS) >> 24;
+               hwrng_msleep(rng, 1000);
        }
 
-       num_words = min(num_words, max_words);
+       num_words = rng_readl(priv, RNG_STATUS) >> 24;
+       if (num_words > max_words)
+               num_words = max_words;
 
        for (count = 0; count < num_words; count++)
                ((u32 *)buf)[count] = rng_readl(priv, RNG_DATA);