Re: [PATCH 4/8] scsi: megaraid_sas - check max_sgl reported by FWfor setting max_sectors_per_req

From: Randy Dunlap
Date: Fri Sep 28 2007 - 16:46:58 EST


On Wed, 26 Sep 2007 11:35:36 -0400 bo yang wrote:

> 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 | 13 +++++++++----
> drivers/scsi/megaraid/megaraid_sas.h | 2 +-
> 2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff -uprN 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 2007-09-27 20:40:14.000000000 -0700
> +++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c 2007-09-27 04:39:44.000000000 -0700
> @@ -1960,6 +1960,7 @@ 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;
> /*
> @@ -2052,17 +2053,21 @@ 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)
> + tmp_sectors = (max_sectors_1 < max_sectors_2)
> ? max_sectors_1 : max_sectors_2;

tmp_sectors = min_t(u32, max_sectors_1, max_sectors_2);

> - } else
> - instance->max_sectors_per_req = instance->max_num_sge *
> - PAGE_SIZE / 512;
> + }
> +
> + 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);


---
~Randy
Phaedrus says that Quality is about caring.
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