This patch will add capability in driver to tell firmware that it can throttle IOs in case Controller's Queue depth is downgraded post OFU
(Online firmware upgrade). This feature will ensure firmware can be downgraded from higher queue depth to lower queue depth without needing system reboot.
Added throttling code in IO path of driver, in case OS tries to send more IOs than post OFU firmware's queue depth.
I have accomodated Tomas' comments provided on last time sent patch- removed the un-necessary code of throttling of IOs against can_queue inside
function- megasas_build_and_issue_cmd_fusion() as SCSI mid layer will anyways does this.
Signed-off-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxxx>
Signed-off-by: Kashyap Desai <kashyap.desai@xxxxxxxxxxxxx>
---
drivers/scsi/megaraid/megaraid_sas.h | 6 ++++--
drivers/scsi/megaraid/megaraid_sas_fusion.c | 1 +
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 2a2f491..c8d25a7 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1537,7 +1537,8 @@ union megasas_sgl_frame {
typedef union _MFI_CAPABILITIES {
struct {
#if defined(__BIG_ENDIAN_BITFIELD)
- u32 reserved:21;
+ u32 reserved:20;
+ u32 support_qd_throttling:1;
u32 support_fp_rlbypass:1;
u32 support_vfid_in_ioframe:1;
u32 support_ext_io_size:1;
@@ -1561,7 +1562,8 @@ typedef union _MFI_CAPABILITIES {
u32 support_ext_io_size:1;
u32 support_vfid_in_ioframe:1;
u32 support_fp_rlbypass:1;
- u32 reserved:21;
+ u32 support_qd_throttling:1;
+ u32 reserved:20;
#endif
} mfi_capabilities;
__le32 reg;
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index 6b8547c..2c4912f 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -803,6 +803,7 @@ megasas_ioc_init_fusion(struct megasas_instance *instance)
if (!dual_qdepth_disable)
drv_ops->mfi_capabilities.support_ext_queue_depth = 1;
+ drv_ops->mfi_capabilities.support_qd_throttling = 1;
/* Convert capability to LE32 */
cpu_to_le32s((u32 *)&init_frame->driver_operations.mfi_capabilities);
--
1.8.3.1
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