hwrng: stm32 - don't read if data is not available

If buffer is being filled up, stop reading instead of reading 0. Change-Id: Idbb44823dbf701793f5af88ca7c2b4fa2a050230 Signed-off-by: Sebastien PASDELOUP <[email protected]> Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/326899 ACI: CITOOLS <[email protected]> Reviewed-by: Gatien CHEVALLIER <[email protected]> Domain-Review: Gatien CHEVALLIER <[email protected]>
STMicroelectronics · Sep 13, 2023 · 94c9fea · 94c9fea
1 parent 3dcc20d
commit 94c9fea
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
@@ -64,6 +64,9 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 					"bad RNG status - %x\n", sr))
 				writel_relaxed(0, priv->base + RNG_SR);
 			break;
+		} else if (!sr) {
+			/* The FIFO is being filled up */
+			break;
 		}
 
 		*(u32 *)data = readl_relaxed(priv->base + RNG_DR);