diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/s390/char/sclp.c | 70 |
1 files changed, 49 insertions, 21 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index 8a056df09d6..3457a9a3157 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(); } |