From 341b7cde6ccc60672fcd7fc84dd24a1b7c0b8d94 Mon Sep 17 00:00:00 2001 From: Ido Yariv Date: Thu, 31 Mar 2011 10:07:01 +0200 Subject: [PATCH] wl12xx: Handle platforms without level trigger interrupts Some platforms are incapable of triggering on level interrupts. Add a platform quirks member in the platform data structure, as well as an edge interrupt quirk which can be set on such platforms. When the interrupt is requested with IRQF_TRIGGER_RISING, IRQF_ONESHOT cannot be used, as we might miss interrupts that occur after the FW status is cleared and before the threaded interrupt handler exits. Moreover, when IRQF_ONESHOT is not set, iterating more than once in the threaded interrupt handler introduces a few race conditions between this handler and the hardirq handler. Currently this is worked around by limiting the loop to one iteration only. This workaround has an impact on performance. To remove to this restriction, the race conditions will need to be addressed. Signed-off-by: Ido Yariv Signed-off-by: Luciano Coelho --- drivers/net/wireless/wl12xx/main.c | 9 +++++++++ drivers/net/wireless/wl12xx/sdio.c | 9 ++++++++- drivers/net/wireless/wl12xx/spi.c | 9 ++++++++- drivers/net/wireless/wl12xx/wl12xx.h | 3 +++ include/linux/wl12xx.h | 4 ++++ 5 files changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c index 1feb9551ef8f..7126506611c1 100644 --- a/drivers/net/wireless/wl12xx/main.c +++ b/drivers/net/wireless/wl12xx/main.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "wl12xx.h" #include "wl12xx_80211.h" @@ -719,6 +720,13 @@ irqreturn_t wl1271_irq(int irq, void *cookie) set_bit(WL1271_FLAG_TX_PENDING, &wl->flags); cancel_work_sync(&wl->tx_work); + /* + * In case edge triggered interrupt must be used, we cannot iterate + * more than once without introducing race conditions with the hardirq. + */ + if (wl->platform_quirks & WL12XX_PLATFORM_QUIRK_EDGE_IRQ) + loopcount = 1; + mutex_lock(&wl->mutex); wl1271_debug(DEBUG_IRQ, "IRQ work"); @@ -3648,6 +3656,7 @@ struct ieee80211_hw *wl1271_alloc_hw(void) wl->ap_ps_map = 0; wl->ap_fw_ps_map = 0; wl->quirks = 0; + wl->platform_quirks = 0; memset(wl->tx_frames_map, 0, sizeof(wl->tx_frames_map)); for (i = 0; i < ACX_TX_DESCRIPTORS; i++) diff --git a/drivers/net/wireless/wl12xx/sdio.c b/drivers/net/wireless/wl12xx/sdio.c index 8246e9de4306..bcd4ad7ba90d 100644 --- a/drivers/net/wireless/wl12xx/sdio.c +++ b/drivers/net/wireless/wl12xx/sdio.c @@ -220,6 +220,7 @@ static int __devinit wl1271_probe(struct sdio_func *func, struct ieee80211_hw *hw; const struct wl12xx_platform_data *wlan_data; struct wl1271 *wl; + unsigned long irqflags; int ret; /* We are only able to handle the wlan function */ @@ -251,9 +252,15 @@ static int __devinit wl1271_probe(struct sdio_func *func, wl->irq = wlan_data->irq; wl->ref_clock = wlan_data->board_ref_clock; wl->tcxo_clock = wlan_data->board_tcxo_clock; + wl->platform_quirks = wlan_data->platform_quirks; + + if (wl->platform_quirks & WL12XX_PLATFORM_QUIRK_EDGE_IRQ) + irqflags = IRQF_TRIGGER_RISING; + else + irqflags = IRQF_TRIGGER_HIGH | IRQF_ONESHOT; ret = request_threaded_irq(wl->irq, wl1271_hardirq, wl1271_irq, - IRQF_TRIGGER_HIGH | IRQF_ONESHOT, + irqflags, DRIVER_NAME, wl); if (ret < 0) { wl1271_error("request_irq() failed: %d", ret); diff --git a/drivers/net/wireless/wl12xx/spi.c b/drivers/net/wireless/wl12xx/spi.c index 7b82b5f0e490..51662bb68019 100644 --- a/drivers/net/wireless/wl12xx/spi.c +++ b/drivers/net/wireless/wl12xx/spi.c @@ -364,6 +364,7 @@ static int __devinit wl1271_probe(struct spi_device *spi) struct wl12xx_platform_data *pdata; struct ieee80211_hw *hw; struct wl1271 *wl; + unsigned long irqflags; int ret; pdata = spi->dev.platform_data; @@ -402,6 +403,12 @@ static int __devinit wl1271_probe(struct spi_device *spi) wl->ref_clock = pdata->board_ref_clock; wl->tcxo_clock = pdata->board_tcxo_clock; + wl->platform_quirks = pdata->platform_quirks; + + if (wl->platform_quirks & WL12XX_PLATFORM_QUIRK_EDGE_IRQ) + irqflags = IRQF_TRIGGER_RISING; + else + irqflags = IRQF_TRIGGER_HIGH | IRQF_ONESHOT; wl->irq = spi->irq; if (wl->irq < 0) { @@ -411,7 +418,7 @@ static int __devinit wl1271_probe(struct spi_device *spi) } ret = request_threaded_irq(wl->irq, wl1271_hardirq, wl1271_irq, - IRQF_TRIGGER_HIGH | IRQF_ONESHOT, + irqflags, DRIVER_NAME, wl); if (ret < 0) { wl1271_error("request_irq() failed: %d", ret); diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h index 9ccbcfdd0802..fb2b79fa42b4 100644 --- a/drivers/net/wireless/wl12xx/wl12xx.h +++ b/drivers/net/wireless/wl12xx/wl12xx.h @@ -579,6 +579,9 @@ struct wl1271 { /* Quirks of specific hardware revisions */ unsigned int quirks; + + /* Platform limitations */ + unsigned int platform_quirks; }; struct wl1271_station { diff --git a/include/linux/wl12xx.h b/include/linux/wl12xx.h index c1a743ea7470..4b697395326e 100644 --- a/include/linux/wl12xx.h +++ b/include/linux/wl12xx.h @@ -53,8 +53,12 @@ struct wl12xx_platform_data { bool use_eeprom; int board_ref_clock; int board_tcxo_clock; + unsigned long platform_quirks; }; +/* Platform does not support level trigger interrupts */ +#define WL12XX_PLATFORM_QUIRK_EDGE_IRQ BIT(0) + #ifdef CONFIG_WL12XX_PLATFORM_DATA int wl12xx_set_platform_data(const struct wl12xx_platform_data *data); -- 2.20.1