From: Eric Biggers <ebiggers@kernel.org>
Date: Sun, 31 May 2026 19:17:36 +0000 (-0700)
Subject: crypto: xilinx-trng - Fix return value of xtrng_hwrng_trng_read()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2dd67774228930ccf6441e5628996021f410c4e0;p=thirdparty%2Flinux.git

crypto: xilinx-trng - Fix return value of xtrng_hwrng_trng_read()

Implementations of hwrng::read are expected to return the number of
bytes generated.  Update xtrng_hwrng_trng_read() to match that.

Fixes: 8979744aca80 ("crypto: xilinx - Add TRNG driver for Versal")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/drivers/crypto/xilinx/xilinx-trng.c b/drivers/crypto/xilinx/xilinx-trng.c
index a35643baa4899..a30b0b3b3685f 100644
--- a/drivers/crypto/xilinx/xilinx-trng.c
+++ b/drivers/crypto/xilinx/xilinx-trng.c
@@ -239,18 +239,21 @@ static int xtrng_hwrng_trng_read(struct hwrng *hwrng, void *data, size_t max, bo
 {
 	u8 buf[TRNG_SEC_STRENGTH_BYTES];
 	struct xilinx_rng *rng;
-	int ret = -EINVAL, i = 0;
+	int ret = 0, i = 0;
 
 	rng = container_of(hwrng, struct xilinx_rng, trng);
 	while (i < max) {
 		ret = xtrng_random_bytes_generate(rng, buf, TRNG_SEC_STRENGTH_BYTES, wait);
-		if (ret < 0)
+		if (ret < 0) {
+			if (i == 0)
+				return ret;
 			break;
+		}
 
 		memcpy(data + i, buf, min_t(int, ret, (max - i)));
 		i += min_t(int, ret, (max - i));
 	}
-	return ret;
+	return i;
 }
 
 static int xtrng_hwrng_register(struct hwrng *trng)