diff mbox series

[net,1/1] s390/ism: clear dmbe_mask bit before SMC IRQ handling

Message ID 20181112160612.31936-1-ubraun@linux.ibm.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series [net,1/1] s390/ism: clear dmbe_mask bit before SMC IRQ handling | expand

Commit Message

Ursula Braun Nov. 12, 2018, 4:06 p.m. UTC 
SMC-D stress workload showed connection stalls. Since the firmware
decides to skip raising an interrupt if the SBA DMBE mask bit is
still set, this SBA DMBE mask bit should be cleared before the
IRQ handling in the SMC code runs. Otherwise there are small windows
possible with missing interrupts for incoming data.
SMC-D currently does not care about the old value of the SBA DMBE
mask.

Acked-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 drivers/s390/net/ism_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
index f96ec68af2e5..dcbf5c857743 100644
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -415,9 +415,9 @@  static irqreturn_t ism_handle_irq(int irq, void *data)
 			break;
 
 		clear_bit_inv(bit, bv);
+		ism->sba->dmbe_mask[bit + ISM_DMB_BIT_OFFSET] = 0;
 		barrier();
 		smcd_handle_irq(ism->smcd, bit + ISM_DMB_BIT_OFFSET);
-		ism->sba->dmbe_mask[bit + ISM_DMB_BIT_OFFSET] = 0;
 	}
 
 	if (ism->sba->e) {