From: Shiji Yang Date: Sat, 4 Nov 2023 08:57:58 +0000 (+0800) Subject: wifi: rt2x00: introduce DMA busy check watchdog for rt2800 X-Git-Tag: microblaze-v6.10~625^2~264^2~30 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=b1275cdd7456ef811747dfb4f3c46310ddd300cd;p=linux-2.6-microblaze.git wifi: rt2x00: introduce DMA busy check watchdog for rt2800 When I tried to fix the watchdog of rt2800, I found that sometimes the watchdog can not reset the hung device. This is because the queue is not completely stuck, it just becomes very slow. The MTK vendor driver for the new chip MT7603/MT7612 has a DMA busy watchdog to detect device hangs by checking DMA busy status. This watchdog implementation is something similar to it. To reduce unnecessary reset, we can check the INT_SOURCE_CSR register together as I found that when the radio hung, the RX/TX coherent interrupt will always stuck at triggered state. The 'watchdog' module parameter has been extended to control all watchdogs(0=disabled, 1=hang watchdog, 2=DMA watchdog, 3=both). This new watchdog function is a slight schedule and it won't affect the transmission speed. So we can turn on it by default. Due to the INT_SOURCE_CSR register is invalid on rt2800 USB NICs, the DMA busy watchdog will be automatically disabled for them. Tested on MT7620 and RT5350. Signed-off-by: Shiji Yang Acked-by: Stanislaw Gruszka Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/TYAP286MB0315D7462CE08A119A99DE34BCA4A@TYAP286MB0315.JPNP286.PROD.OUTLOOK.COM --- diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800.h b/drivers/net/wireless/ralink/rt2x00/rt2800.h index 48521e45577d..8930589b4967 100644 --- a/drivers/net/wireless/ralink/rt2x00/rt2800.h +++ b/drivers/net/wireless/ralink/rt2x00/rt2800.h @@ -3194,4 +3194,8 @@ enum rt2800_eeprom_word { */ #define BCN_TBTT_OFFSET 64 +/* Watchdog type mask */ +#define RT2800_WATCHDOG_HANG BIT(0) +#define RT2800_WATCHDOG_DMA_BUSY BIT(1) + #endif /* RT2800_H */ diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c index ee880f749b3c..532b6c60c8b1 100644 --- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c +++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c @@ -30,9 +30,10 @@ #include "rt2800lib.h" #include "rt2800.h" -static bool modparam_watchdog; -module_param_named(watchdog, modparam_watchdog, bool, S_IRUGO); -MODULE_PARM_DESC(watchdog, "Enable watchdog to detect tx/rx hangs and reset hardware if detected"); +static unsigned int modparam_watchdog = RT2800_WATCHDOG_DMA_BUSY; +module_param_named(watchdog, modparam_watchdog, uint, 0444); +MODULE_PARM_DESC(watchdog, "Enable watchdog to recover tx/rx hangs.\n" + "\t\t(0=disabled, 1=hang watchdog, 2=DMA watchdog(default), 3=both)"); /* * Register access. @@ -1261,15 +1262,12 @@ static void rt2800_update_survey(struct rt2x00_dev *rt2x00dev) chan_survey->time_ext_busy += rt2800_register_read(rt2x00dev, CH_BUSY_STA_SEC); } -void rt2800_watchdog(struct rt2x00_dev *rt2x00dev) +static bool rt2800_watchdog_hung(struct rt2x00_dev *rt2x00dev) { struct data_queue *queue; bool hung_tx = false; bool hung_rx = false; - if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags)) - return; - rt2800_update_survey(rt2x00dev); queue_for_each(rt2x00dev, queue) { @@ -1297,18 +1295,72 @@ void rt2800_watchdog(struct rt2x00_dev *rt2x00dev) } } + if (!hung_tx && !hung_rx) + return false; + if (hung_tx) rt2x00_warn(rt2x00dev, "Watchdog TX hung detected\n"); if (hung_rx) rt2x00_warn(rt2x00dev, "Watchdog RX hung detected\n"); - if (hung_tx || hung_rx) { - queue_for_each(rt2x00dev, queue) - queue->wd_count = 0; + queue_for_each(rt2x00dev, queue) + queue->wd_count = 0; + + return true; +} + +static bool rt2800_watchdog_dma_busy(struct rt2x00_dev *rt2x00dev) +{ + bool busy_rx, busy_tx; + u32 reg_cfg = rt2800_register_read(rt2x00dev, WPDMA_GLO_CFG); + u32 reg_int = rt2800_register_read(rt2x00dev, INT_SOURCE_CSR); + + if (rt2x00_get_field32(reg_cfg, WPDMA_GLO_CFG_RX_DMA_BUSY) && + rt2x00_get_field32(reg_int, INT_SOURCE_CSR_RX_COHERENT)) + rt2x00dev->rxdma_busy++; + else + rt2x00dev->rxdma_busy = 0; + if (rt2x00_get_field32(reg_cfg, WPDMA_GLO_CFG_TX_DMA_BUSY) && + rt2x00_get_field32(reg_int, INT_SOURCE_CSR_TX_COHERENT)) + rt2x00dev->txdma_busy++; + else + rt2x00dev->txdma_busy = 0; + + busy_rx = rt2x00dev->rxdma_busy > 30 ? true : false; + busy_tx = rt2x00dev->txdma_busy > 30 ? true : false; + + if (!busy_rx && !busy_tx) + return false; + + if (busy_rx) + rt2x00_warn(rt2x00dev, "Watchdog RX DMA busy detected\n"); + + if (busy_tx) + rt2x00_warn(rt2x00dev, "Watchdog TX DMA busy detected\n"); + + rt2x00dev->rxdma_busy = 0; + rt2x00dev->txdma_busy = 0; + + return true; +} + +void rt2800_watchdog(struct rt2x00_dev *rt2x00dev) +{ + bool reset = false; + + if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags)) + return; + + if (modparam_watchdog & RT2800_WATCHDOG_DMA_BUSY) + reset = rt2800_watchdog_dma_busy(rt2x00dev); + + if (modparam_watchdog & RT2800_WATCHDOG_HANG) + reset = rt2800_watchdog_hung(rt2x00dev) || reset; + + if (reset) ieee80211_restart_hw(rt2x00dev->hw); - } } EXPORT_SYMBOL_GPL(rt2800_watchdog); @@ -12013,6 +12065,9 @@ int rt2800_probe_hw(struct rt2x00_dev *rt2x00dev) __set_bit(REQUIRE_TASKLET_CONTEXT, &rt2x00dev->cap_flags); } + /* USB NICs don't support DMA watchdog as INT_SOURCE_CSR is invalid */ + if (rt2x00_is_usb(rt2x00dev)) + modparam_watchdog &= ~RT2800_WATCHDOG_DMA_BUSY; if (modparam_watchdog) { __set_bit(CAPABILITY_RESTART_HW, &rt2x00dev->cap_flags); rt2x00dev->link.watchdog_interval = msecs_to_jiffies(100); diff --git a/drivers/net/wireless/ralink/rt2x00/rt2x00.h b/drivers/net/wireless/ralink/rt2x00/rt2x00.h index aaaf99331967..62fed38f41c0 100644 --- a/drivers/net/wireless/ralink/rt2x00/rt2x00.h +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00.h @@ -926,6 +926,9 @@ struct rt2x00_dev { */ u16 beacon_int; + /* Rx/Tx DMA busy watchdog counter */ + u16 rxdma_busy, txdma_busy; + /** * Timestamp of last received beacon */