1 files changed, 49 insertions, 21 deletions

diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 8a056df09d6b..3457a9a31571 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -59,7 +59,8 @@ static volatile enum sclp_init_state_t {
 /* Internal state: is a request active at the sclp? */
 static volatile enum sclp_running_state_t {
         sclp_running_state_idle,
-        sclp_running_state_running
+        sclp_running_state_running,
+        sclp_running_state_reset_pending
 } sclp_running_state = sclp_running_state_idle;
 
 /* Internal state: is a read request pending? */
@@ -88,7 +89,7 @@ static volatile enum sclp_mask_state_t {
 
 /* Timeout intervals in seconds.*/
 #define SCLP_BUSY_INTERVAL      10
-#define SCLP_RETRY_INTERVAL     15
+#define SCLP_RETRY_INTERVAL     30
 
 static void sclp_process_queue(void);
 static int sclp_init_mask(int calculate);
@@ -113,19 +114,17 @@ service_call(sclp_cmdw_t command, void *sccb)
         return 0;
 }
 
-/* Request timeout handler. Restart the request queue. If DATA is non-zero,
- * force restart of running request. */
+static inline void __sclp_make_read_req(void);
+
 static void
-sclp_request_timeout(unsigned long data)
+__sclp_queue_read_req(void)
 {
-        unsigned long flags;
-
-        if (data) {
-                spin_lock_irqsave(&sclp_lock, flags);
-                sclp_running_state = sclp_running_state_idle;
-                spin_unlock_irqrestore(&sclp_lock, flags);
+        if (sclp_reading_state == sclp_reading_state_idle) {
+                sclp_reading_state = sclp_reading_state_reading;
+                __sclp_make_read_req();
+                /* Add request to head of queue */
+                list_add(&sclp_read_req.list, &sclp_req_queue);
         }
-        sclp_process_queue();
 }
 
 /* Set up request retry timer. Called while sclp_lock is locked. */
@@ -140,6 +139,29 @@ __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long),
         add_timer(&sclp_request_timer);
 }
 
+/* Request timeout handler. Restart the request queue. If DATA is non-zero,
+ * force restart of running request. */
+static void
+sclp_request_timeout(unsigned long data)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&sclp_lock, flags);
+        if (data) {
+                if (sclp_running_state == sclp_running_state_running) {
+                        /* Break running state and queue NOP read event request
+                         * to get a defined interface state. */
+                        __sclp_queue_read_req();
+                        sclp_running_state = sclp_running_state_idle;
+                }
+        } else {
+                __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
+                                         sclp_request_timeout, 0);
+        }
+        spin_unlock_irqrestore(&sclp_lock, flags);
+        sclp_process_queue();
+}
+
 /* Try to start a request. Return zero if the request was successfully
  * started or if it will be started at a later time. Return non-zero otherwise.
  * Called while sclp_lock is locked. */
@@ -191,7 +213,15 @@ sclp_process_queue(void)
                 rc = __sclp_start_request(req);
                 if (rc == 0)
                         break;
-                /* Request failed. */
+                /* Request failed */
+                if (req->start_count > 1) {
+                        /* Cannot abort already submitted request - could still
+                         * be active at the SCLP */
+                        __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
+                                                 sclp_request_timeout, 0);
+                        break;
+                }
+                /* Post-processing for aborted request */
                 list_del(&req->list);
                 if (req->callback) {
                         spin_unlock_irqrestore(&sclp_lock, flags);
@@ -221,7 +251,8 @@ sclp_add_request(struct sclp_req *req)
         list_add_tail(&req->list, &sclp_req_queue);
         rc = 0;
         /* Start if request is first in list */
-        if (req->list.prev == &sclp_req_queue) {
+        if (sclp_running_state == sclp_running_state_idle &&
+            req->list.prev == &sclp_req_queue) {
                 rc = __sclp_start_request(req);
                 if (rc)
                         list_del(&req->list);
@@ -334,6 +365,8 @@ sclp_interrupt_handler(__u16 code)
         finished_sccb = S390_lowcore.ext_params & 0xfffffff8;
         evbuf_pending = S390_lowcore.ext_params & 0x3;
         if (finished_sccb) {
+                del_timer(&sclp_request_timer);
+                sclp_running_state = sclp_running_state_reset_pending;
                 req = __sclp_find_req(finished_sccb);
                 if (req) {
                         /* Request post-processing */
@@ -348,13 +381,8 @@ sclp_interrupt_handler(__u16 code)
                 sclp_running_state = sclp_running_state_idle;
         }
         if (evbuf_pending && sclp_receive_mask != 0 &&
-            sclp_reading_state == sclp_reading_state_idle &&
-            sclp_activation_state == sclp_activation_state_active ) {
-                sclp_reading_state = sclp_reading_state_reading;
-                __sclp_make_read_req();
-                /* Add request to head of queue */
-                list_add(&sclp_read_req.list, &sclp_req_queue);
-        }
+            sclp_activation_state == sclp_activation_state_active)
+                __sclp_queue_read_req();
         spin_unlock(&sclp_lock);
         sclp_process_queue();
 }