HSI: ssi_protocol: avoid ssi_waketest call with held spinlock

This avoids calling ssi_waketest(), while a spinlock is
being hold, since ssi_waketest may sleep once irq_safe
runtime pm is disabled.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-by: Pavel Machek <pavel@ucw.cz>

1 files changed, 25 insertions, 16 deletions

diff --git a/drivers/hsi/clients/ssi_protocol.c b/drivers/hsi/clients/ssi_protocol.c
index 6595d2091268..8534efda8140 100644
--- a/drivers/hsi/clients/ssi_protocol.c
+++ b/drivers/hsi/clients/ssi_protocol.c
@@ -88,6 +88,8 @@ void ssi_waketest(struct hsi_client *cl, unsigned int enable);
 #define SSIP_READY_CMD          SSIP_CMD(SSIP_READY, 0)
 #define SSIP_SWBREAK_CMD        SSIP_CMD(SSIP_SW_BREAK, 0)
 
+#define SSIP_WAKETEST_FLAG 0
+
 /* Main state machine states */
 enum {
         INIT,
@@ -116,7 +118,7 @@ enum {
  * @main_state: Main state machine
  * @send_state: TX state machine
  * @recv_state: RX state machine
- * @waketest: Flag to follow wake line test
+ * @flags: Flags, currently only used to follow wake line test
  * @rxid: RX data id
  * @txid: TX data id
  * @txqueue_len: TX queue length
@@ -137,7 +139,7 @@ struct ssi_protocol {
         unsigned int            main_state;
         unsigned int            send_state;
         unsigned int            recv_state;
-        unsigned int            waketest:1;
+        unsigned long           flags;
         u8                      rxid;
         u8                      txid;
         unsigned int            txqueue_len;
@@ -405,15 +407,17 @@ static void ssip_reset(struct hsi_client *cl)
         spin_lock_bh(&ssi->lock);
         if (ssi->send_state != SEND_IDLE)
                 hsi_stop_tx(cl);
-        if (ssi->waketest)
-                ssi_waketest(cl, 0);
+        spin_unlock_bh(&ssi->lock);
+        if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
+                ssi_waketest(cl, 0); /* FIXME: To be removed */
+        spin_lock_bh(&ssi->lock);
         del_timer(&ssi->rx_wd);
         del_timer(&ssi->tx_wd);
         del_timer(&ssi->keep_alive);
         ssi->main_state = 0;
         ssi->send_state = 0;
         ssi->recv_state = 0;
-        ssi->waketest = 0;
+        ssi->flags = 0;
         ssi->rxid = 0;
         ssi->txid = 0;
         list_for_each_safe(head, tmp, &ssi->txqueue) {
@@ -437,7 +441,8 @@ static void ssip_dump_state(struct hsi_client *cl)
         dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
         dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
                                                         "Online" : "Offline");
-        dev_err(&cl->device, "Wake test %d\n", ssi->waketest);
+        dev_err(&cl->device, "Wake test %d\n",
+                                test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
         dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
         dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
 
@@ -668,10 +673,12 @@ static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
         case HANDSHAKE:
                 spin_lock(&ssi->lock);
                 ssi->main_state = HANDSHAKE;
-                if (!ssi->waketest) {
-                        ssi->waketest = 1;
+                spin_unlock(&ssi->lock);
+
+                if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
                         ssi_waketest(cl, 1); /* FIXME: To be removed */
-                }
+
+                spin_lock(&ssi->lock);
                 /* Start boot handshake watchdog */
                 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
                 spin_unlock(&ssi->lock);
@@ -718,10 +725,12 @@ static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
                 spin_unlock(&ssi->lock);
                 return;
         }
-        if (ssi->waketest) {
-                ssi->waketest = 0;
+        spin_unlock(&ssi->lock);
+
+        if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
                 ssi_waketest(cl, 0); /* FIXME: To be removed */
-        }
+
+        spin_lock(&ssi->lock);
         ssi->main_state = ACTIVE;
         del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
         spin_unlock(&ssi->lock);
@@ -926,11 +935,11 @@ static int ssip_pn_open(struct net_device *dev)
         }
         dev_dbg(&cl->device, "Configuring SSI port\n");
         hsi_setup(cl);
-        spin_lock_bh(&ssi->lock);
-        if (!ssi->waketest) {
-                ssi->waketest = 1;
+
+        if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
                 ssi_waketest(cl, 1); /* FIXME: To be removed */
-        }
+
+        spin_lock_bh(&ssi->lock);
         ssi->main_state = HANDSHAKE;
         spin_unlock_bh(&ssi->lock);