"Jason A. Donenfeld" [off-list ref] writes:

Hardware random number generators are supposed to use the hw_random
framework. This commit turns ath9k's kthread-based design into a proper
hw_random driver.

This compiles, but I have no hardware or other ability to determine
whether it works. I'll leave further development up to the ath9k
and hw_random maintainers.

Cc: Toke Høiland-Jørgensen <redacted>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

[...]

+retry:
+	if (max & ~3UL)
+		bytes_read = ath9k_rng_data_read(sc, buf, max >> 2);
+	if ((max & 3UL) && ath9k_rng_data_read(sc, &word, 1)) {
+		memcpy(buf + bytes_read, &word, max & 3);
+		bytes_read += max & 3;
+		memzero_explicit(&word, sizeof(word));
+	}
+	if (max && unlikely(!bytes_read) && wait) {
+		msleep(ath9k_rng_delay_get(++fail_stats));
+		goto retry;
 	}

Wouldn't a while loop be cleaner? With a some kind limit for the number
of loops, to avoid a neverending loop.

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