From bffbbd2df4196a73ffdc16709866dd96eb66aad8 Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Wed, 20 Apr 2011 10:15:33 +0200 Subject: [PATCH] [S390] qdio: reset error states immediately The qdio hardware may surpress further interrupts as long as a SBAL is in the error state. That can lead to unnotified data in the SBALs following the error state. To prevent this behaviour change the SBAL[s] in error state immediately to another program owned state so interrupts are again received for further traffic on the device. Signed-off-by: Jan Glauber Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_main.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index c532ba929ccd..e8f267eb8887 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -407,8 +407,11 @@ static inline void account_sbals(struct qdio_q *q, int count) q->q_stats.nr_sbals[pos]++; } -static void announce_buffer_error(struct qdio_q *q, int count) +static void process_buffer_error(struct qdio_q *q, int count) { + unsigned char state = (q->is_input_q) ? SLSB_P_INPUT_NOT_INIT : + SLSB_P_OUTPUT_NOT_INIT; + q->qdio_error |= QDIO_ERROR_SLSB_STATE; /* special handling for no target buffer empty */ @@ -426,6 +429,12 @@ static void announce_buffer_error(struct qdio_q *q, int count) DBF_ERROR("F14:%2x F15:%2x", q->sbal[q->first_to_check]->element[14].flags & 0xff, q->sbal[q->first_to_check]->element[15].flags & 0xff); + + /* + * Interrupts may be avoided as long as the error is present + * so change the buffer state immediately to avoid starvation. + */ + set_buf_states(q, q->first_to_check, state, count); } static inline void inbound_primed(struct qdio_q *q, int count) @@ -506,8 +515,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) account_sbals(q, count); break; case SLSB_P_INPUT_ERROR: - announce_buffer_error(q, count); - /* process the buffer, the upper layer will take care of it */ + process_buffer_error(q, count); q->first_to_check = add_buf(q->first_to_check, count); atomic_sub(count, &q->nr_buf_used); if (q->irq_ptr->perf_stat_enabled) @@ -677,8 +685,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) account_sbals(q, count); break; case SLSB_P_OUTPUT_ERROR: - announce_buffer_error(q, count); - /* process the buffer, the upper layer will take care of it */ + process_buffer_error(q, count); q->first_to_check = add_buf(q->first_to_check, count); atomic_sub(count, &q->nr_buf_used); if (q->irq_ptr->perf_stat_enabled) -- 2.11.0