diff options
Diffstat (limited to 'drivers/net/wireless/ath9k/hw.c')
| -rw-r--r-- | drivers/net/wireless/ath9k/hw.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath9k/hw.c b/drivers/net/wireless/ath9k/hw.c index 34474edefc97..5c870436fc5f 100644 --- a/drivers/net/wireless/ath9k/hw.c +++ b/drivers/net/wireless/ath9k/hw.c @@ -437,6 +437,25 @@ static void ath9k_hw_set_defaults(struct ath_hal *ah) } ah->ah_config.intr_mitigation = 1; + + /* + * We need this for PCI devices only (Cardbus, PCI, miniPCI) + * _and_ if on non-uniprocessor systems (Multiprocessor/HT). + * This means we use it for all AR5416 devices, and the few + * minor PCI AR9280 devices out there. + * + * Serialization is required because these devices do not handle + * well the case of two concurrent reads/writes due to the latency + * involved. During one read/write another read/write can be issued + * on another CPU while the previous read/write may still be working + * on our hardware, if we hit this case the hardware poops in a loop. + * We prevent this by serializing reads and writes. + * + * This issue is not present on PCI-Express devices or pre-AR5416 + * devices (legacy, 802.11abg). + */ + if (num_possible_cpus() > 1) + ah->ah_config.serialize_regmode = SER_REG_MODE_AUTO; } static struct ath_hal_5416 *ath9k_hw_newstate(u16 devid, |