From f0c543159a4abad4412e55db33ac730c9f21684d 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 commit 413c2f33489b134e3cc65d9c3ff7861e8fdfe899 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 4441a55..34bbcfc 100644 --- a/drivers/scsi/qla2xxx/qla_init.c +++ b/drivers/scsi/qla2xxx/qla_init.c @@ -3319,7 +3319,8 @@ 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, -- 2.7.4