wl1271: Implement chipset boot retry

The wl1271 has a hardware bug which causes it to randomly (very infrequently)
to fail powering up properly. This patch implements retry for the chipset boot
sequence, to work around the hardware problem.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index d07f03565196c971e183adfc7ce0eec3f6c2821c..0795bf3c60da8c393f48d3941b3ad9187344fea4 100644 (file)
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -47,6 +47,8 @@
 #include "wl1271_cmd.h"
 #include "wl1271_boot.h"
 
+#define WL1271_BOOT_RETRIES 3
+
 static struct conf_drv_settings default_conf = {
        .sg = {
                .per_threshold               = 7500,
@@ -645,7 +647,7 @@ static int wl1271_chip_wakeup(struct wl1271 *wl)
 
                ret = wl1271_setup(wl);
                if (ret < 0)
-                       goto out_power_off;
+                       goto out;
                break;
        case CHIP_ID_1271_PG20:
                wl1271_debug(DEBUG_BOOT, "chip id 0x%x (1271 PG20)",
@@ -653,38 +655,34 @@ static int wl1271_chip_wakeup(struct wl1271 *wl)
 
                ret = wl1271_setup(wl);
                if (ret < 0)
-                       goto out_power_off;
+                       goto out;
                break;
        default:
-               wl1271_error("unsupported chip id: 0x%x", wl->chip.id);
+               wl1271_warning("unsupported chip id: 0x%x", wl->chip.id);
                ret = -ENODEV;
-               goto out_power_off;
+               goto out;
        }
 
        if (wl->fw == NULL) {
                ret = wl1271_fetch_firmware(wl);
                if (ret < 0)
-                       goto out_power_off;
+                       goto out;
        }
 
        /* No NVS from netlink, try to get it from the filesystem */
        if (wl->nvs == NULL) {
                ret = wl1271_fetch_nvs(wl);
                if (ret < 0)
-                       goto out_power_off;
+                       goto out;
        }
 
-       goto out;
-
-out_power_off:
-       wl1271_power_off(wl);
-
 out:
        return ret;
 }
 
 int wl1271_plt_start(struct wl1271 *wl)
 {
+       int retries = WL1271_BOOT_RETRIES;
        int ret;
 
        mutex_lock(&wl->mutex);
@@ -698,35 +696,48 @@ int wl1271_plt_start(struct wl1271 *wl)
                goto out;
        }
 
-       wl->state = WL1271_STATE_PLT;
-
-       ret = wl1271_chip_wakeup(wl);
-       if (ret < 0)
-               goto out;
-
-       ret = wl1271_boot(wl);
-       if (ret < 0)
-               goto out_power_off;
-
-       wl1271_notice("firmware booted in PLT mode (%s)", wl->chip.fw_ver);
+       while (retries) {
+               retries--;
+               ret = wl1271_chip_wakeup(wl);
+               if (ret < 0)
+                       goto power_off;
 
-       ret = wl1271_plt_init(wl);
-       if (ret < 0)
-               goto out_irq_disable;
+               ret = wl1271_boot(wl);
+               if (ret < 0)
+                       goto power_off;
 
-       /* Make sure power saving is disabled */
-       ret = wl1271_acx_sleep_auth(wl, WL1271_PSM_CAM);
-       if (ret < 0)
-               goto out_irq_disable;
+               ret = wl1271_plt_init(wl);
+               if (ret < 0)
+                       goto irq_disable;
 
-       goto out;
+               /* Make sure power saving is disabled */
+               ret = wl1271_acx_sleep_auth(wl, WL1271_PSM_CAM);
+               if (ret < 0)
+                       goto irq_disable;
 
-out_irq_disable:
-       wl1271_disable_interrupts(wl);
+               wl->state = WL1271_STATE_PLT;
+               wl1271_notice("firmware booted in PLT mode (%s)",
+                             wl->chip.fw_ver);
+               goto out;
 
-out_power_off:
-       wl1271_power_off(wl);
+irq_disable:
+               wl1271_disable_interrupts(wl);
+               mutex_unlock(&wl->mutex);
+               /* Unlocking the mutex in the middle of handling is
+                  inherently unsafe. In this case we deem it safe to do,
+                  because we need to let any possibly pending IRQ out of
+                  the system (and while we are WL1271_STATE_OFF the IRQ
+                  work function will not do anything.) Also, any other
+                  possible concurrent operations will fail due to the
+                  current state, hence the wl1271 struct should be safe. */
+               cancel_work_sync(&wl->irq_work);
+               mutex_lock(&wl->mutex);
+power_off:
+               wl1271_power_off(wl);
+       }
 
+       wl1271_error("firmware boot in PLT mode failed despite %d retries",
+                    WL1271_BOOT_RETRIES);
 out:
        mutex_unlock(&wl->mutex);
 
@@ -882,6 +893,7 @@ static struct notifier_block wl1271_dev_notifier = {
 static int wl1271_op_start(struct ieee80211_hw *hw)
 {
        struct wl1271 *wl = hw->priv;
+       int retries = WL1271_BOOT_RETRIES;
        int ret = 0;
 
        wl1271_debug(DEBUG_MAC80211, "mac80211 start");
@@ -895,30 +907,42 @@ static int wl1271_op_start(struct ieee80211_hw *hw)
                goto out;
        }
 
-       ret = wl1271_chip_wakeup(wl);
-       if (ret < 0)
-               goto out;
-
-       ret = wl1271_boot(wl);
-       if (ret < 0)
-               goto out_power_off;
-
-       ret = wl1271_hw_init(wl);
-       if (ret < 0)
-               goto out_irq_disable;
-
-       wl->state = WL1271_STATE_ON;
+       while (retries) {
+               retries--;
+               ret = wl1271_chip_wakeup(wl);
+               if (ret < 0)
+                       goto power_off;
 
-       wl1271_info("firmware booted (%s)", wl->chip.fw_ver);
+               ret = wl1271_boot(wl);
+               if (ret < 0)
+                       goto power_off;
 
-       goto out;
+               ret = wl1271_hw_init(wl);
+               if (ret < 0)
+                       goto irq_disable;
 
-out_irq_disable:
-       wl1271_disable_interrupts(wl);
+               wl->state = WL1271_STATE_ON;
+               wl1271_info("firmware booted (%s)", wl->chip.fw_ver);
+               goto out;
 
-out_power_off:
-       wl1271_power_off(wl);
+irq_disable:
+               wl1271_disable_interrupts(wl);
+               mutex_unlock(&wl->mutex);
+               /* Unlocking the mutex in the middle of handling is
+                  inherently unsafe. In this case we deem it safe to do,
+                  because we need to let any possibly pending IRQ out of
+                  the system (and while we are WL1271_STATE_OFF the IRQ
+                  work function will not do anything.) Also, any other
+                  possible concurrent operations will fail due to the
+                  current state, hence the wl1271 struct should be safe. */
+               cancel_work_sync(&wl->irq_work);
+               mutex_lock(&wl->mutex);
+power_off:
+               wl1271_power_off(wl);
+       }
 
+       wl1271_error("firmware boot failed despite %d retries",
+                    WL1271_BOOT_RETRIES);
 out:
        mutex_unlock(&wl->mutex);