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>

1 files changed, 77 insertions, 53 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index d07f03565196..0795bf3c60da 100644
--- 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);