From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx> If no valid ADC randomness output, ath9k rng will continuously reading ADC, which will cause high CPU load. So increase the delay to wait for ADC ready. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=114261 Signed-off-by: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/rng.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c index c9cb2aa..d38e50f 100644 --- a/drivers/net/wireless/ath/ath9k/rng.c +++ b/drivers/net/wireless/ath/ath9k/rng.c @@ -55,11 +55,26 @@ static int ath9k_rng_data_read(struct ath_softc *sc, u32 *buf, u32 buf_size) return j << 2; } +static u32 ath9k_rng_delay_get(u32 fail_stats) +{ + u32 delay; + + if (fail_stats < 100) + delay = 10; + else if (fail_stats < 105) + delay = 1000; + else + delay = 10000; + + return delay; +} + static int ath9k_rng_kthread(void *data) { int bytes_read; struct ath_softc *sc = data; u32 *rng_buf; + u32 delay, fail_stats = 0; rng_buf = kmalloc_array(ATH9K_RNG_BUF_SIZE, sizeof(u32), GFP_KERNEL); if (!rng_buf) @@ -69,10 +84,13 @@ static int ath9k_rng_kthread(void *data) bytes_read = ath9k_rng_data_read(sc, rng_buf, ATH9K_RNG_BUF_SIZE); if (unlikely(!bytes_read)) { - msleep_interruptible(10); + delay = ath9k_rng_delay_get(++fail_stats); + msleep_interruptible(delay); continue; } + fail_stats = 0; + /* sleep until entropy bits under write_wakeup_threshold */ add_hwgenerator_randomness((void *)rng_buf, bytes_read, ATH9K_RNG_ENTROPY(bytes_read)); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
