[PATCH 2/6] scsi: megaraid_sas - check max_sgl reported by FWforsetting max_sectors_per_req

From: bo yang
Date: Fri Nov 09 2007 - 16:08:41 EST


1. Setting the max_sectors_per_req based on max SGL supported by the FW. Prior versions calculated
this value from controller info's max_sectors_1, max_sectors_2. For certain controllers/FW,
this was resulting in a value greater than max SGL supported by the FW. Now we take the min
of max sgl from FW and max_sectors calculation.

2. Increased MFI_POLL_TIMEOUT_SECS to 60 seconds from 10. FW may take a max of 60 seconds to
respond to the INIT cmd.

Signed-off-by: Bo Yang <bo.yang@xxxxxxx>

---
drivers/scsi/megaraid/megaraid_sas.c | 14 +++++++++-----
drivers/scsi/megaraid/megaraid_sas.h | 2 +-
2 files changed, 10 insertions(+), 6 deletions(-)

diff -rupN linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c
--- linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c 2007-11-07 02:01:52.687143648 -0500
+++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c 2007-11-07 02:26:01.144944592 -0500
@@ -1889,6 +1889,7 @@ static int megasas_init_mfi(struct megas
u32 reply_q_sz;
u32 max_sectors_1;
u32 max_sectors_2;
+ u32 tmp_sectors;
struct megasas_register_set __iomem *reg_set;
struct megasas_ctrl_info *ctrl_info;
/*
@@ -1981,17 +1982,20 @@ static int megasas_init_mfi(struct megas
* Note that older firmwares ( < FW ver 30) didn't report information
* to calculate max_sectors_1. So the number ended up as zero always.
*/
+ tmp_sectors = 0;
if (ctrl_info && !megasas_get_ctrl_info(instance, ctrl_info)) {

max_sectors_1 = (1 << ctrl_info->stripe_sz_ops.min) *
ctrl_info->max_strips_per_io;
max_sectors_2 = ctrl_info->max_request_size;

- instance->max_sectors_per_req = (max_sectors_1 < max_sectors_2)
- ? max_sectors_1 : max_sectors_2;
- } else
- instance->max_sectors_per_req = instance->max_num_sge *
- PAGE_SIZE / 512;
+ tmp_sectors = min_t(u32, max_sectors_1 , max_sectors_2);
+ }
+
+ instance->max_sectors_per_req = instance->max_num_sge *
+ PAGE_SIZE / 512;
+ if (tmp_sectors && (instance->max_sectors_per_req > tmp_sectors))
+ instance->max_sectors_per_req = tmp_sectors;

kfree(ctrl_info);

diff -rupN linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.h linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.h
--- linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.h 2007-11-07 02:01:52.687143648 -0500
+++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.h 2007-11-07 02:21:17.349088120 -0500
@@ -571,7 +571,7 @@ struct megasas_ctrl_info {
#define IS_DMA64 (sizeof(dma_addr_t) == 8)

#define MFI_OB_INTR_STATUS_MASK 0x00000002
-#define MFI_POLL_TIMEOUT_SECS 10
+#define MFI_POLL_TIMEOUT_SECS 60

#define MFI_REPLY_1078_MESSAGE_INTERRUPT 0x80000000


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