From a3e1e55e4b5ca4d49618c592b4d10814e21e12a7 Mon Sep 17 00:00:00 2001 From: "Kashyap, Desai" Date: Tue, 14 Jun 2011 10:56:12 +0530 Subject: [PATCH] [SCSI] mpt2sas: Set max_sector count from module parameter This feature is to override the default max_sectors setting at load time, taking max_sectors as an command line option when loading the driver. The setting is currently hard-coded in the driver to 8192 sectors (4MB transfers). If max_sectors is specified at load time, minimum specified setting will be 64, and the maximum is 8192. The driver will modify the setting to be on even boundary. If max_sectors is not specified, the driver will default to 8192. Signed-off-by: Kashyap Desai Signed-off-by: James Bottomley --- drivers/scsi/mpt2sas/mpt2sas_scsih.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c index e327a3c03608..f86f2b1418e7 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c +++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c @@ -94,6 +94,10 @@ static u32 logging_level; MODULE_PARM_DESC(logging_level, " bits for enabling additional logging info " "(default=0)"); +static ushort max_sectors = 0xFFFF; +module_param(max_sectors, ushort, 0); +MODULE_PARM_DESC(max_sectors, "max sectors, range 64 to 8192 default=8192"); + /* scsi-mid layer global parmeter is max_report_luns, which is 511 */ #define MPT2SAS_MAX_LUN (16895) static int max_lun = MPT2SAS_MAX_LUN; @@ -7436,6 +7440,25 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id) shost->transportt = mpt2sas_transport_template; shost->unique_id = ioc->id; + if (max_sectors != 0xFFFF) { + if (max_sectors < 64) { + shost->max_sectors = 64; + printk(MPT2SAS_WARN_FMT "Invalid value %d passed " + "for max_sectors, range is 64 to 8192. Assigning " + "value of 64.\n", ioc->name, max_sectors); + } else if (max_sectors > 8192) { + shost->max_sectors = 8192; + printk(MPT2SAS_WARN_FMT "Invalid value %d passed " + "for max_sectors, range is 64 to 8192. Assigning " + "default value of 8192.\n", ioc->name, + max_sectors); + } else { + shost->max_sectors = max_sectors & 0xFFFE; + printk(MPT2SAS_INFO_FMT "The max_sectors value is " + "set to %d\n", ioc->name, shost->max_sectors); + } + } + if ((scsi_add_host(shost, &pdev->dev))) { printk(MPT2SAS_ERR_FMT "failure at %s:%d/%s()!\n", ioc->name, __FILE__, __LINE__, __func__); -- 2.39.2