From 413c2f33489b134e3cc65d9c3ff7861e8fdfe899 Mon Sep 17 00:00:00 2001 From: Himanshu Madhani Date: Sun, 3 Jun 2018 22:09:53 -0700 Subject: [PATCH] scsi: qla2xxx: Fix setting lower transfer speed if GPSC fails This patch prevents driver from setting lower default speed of 1 GB/sec, if the switch does not support Get Port Speed Capabilities (GPSC) command. Setting this default speed results into much lower write performance for large sequential WRITE. This patch modifies driver to check for gpsc_supported flags and prevents driver from issuing MBC_SET_PORT_PARAM (001Ah) to set default speed of 1 GB/sec. If driver does not send this mailbox command, firmware assumes maximum supported link speed and will operate at the max speed. Cc: stable@vger.kernel.org Signed-off-by: Himanshu Madhani Reported-by: Eda Zhou Reviewed-by: Ewan D. Milne Tested-by: Ewan D. Milne Signed-off-by: Martin K. Petersen --- drivers/scsi/qla2xxx/qla_init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c index 8f55dd44adae..636960ad029a 100644 --- a/drivers/scsi/qla2xxx/qla_init.c +++ b/drivers/scsi/qla2xxx/qla_init.c @@ -5037,7 +5037,8 @@ qla2x00_iidma_fcport(scsi_qla_host_t *vha, fc_port_t *fcport) return; if (fcport->fp_speed == PORT_SPEED_UNKNOWN || - fcport->fp_speed > ha->link_data_rate) + fcport->fp_speed > ha->link_data_rate || + !ha->flags.gpsc_supported) return; rval = qla2x00_set_idma_speed(vha, fcport->loop_id, fcport->fp_speed,