From 21db1882f79a1ad5977cae6766376a63f60ec414 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 22 Nov 2006 13:24:52 -0700 Subject: [PATCH] [SCSI] Add Kconfig option for asynchronous SCSI scanning Without this patch, the user has to add a kernel command line parameter to get asynchronous SCSI scanning. Now they can select the default at compile time and still override it at boot time if they need to. Signed-off-by: Matthew Wilcox Signed-off-by: James Bottomley --- drivers/scsi/Kconfig | 17 +++++++++++++++++ drivers/scsi/scsi_scan.c | 8 +++++++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig index 5881464a938d..8442be1bb162 100644 --- a/drivers/scsi/Kconfig +++ b/drivers/scsi/Kconfig @@ -216,6 +216,23 @@ config SCSI_LOGGING there should be no noticeable performance impact as long as you have logging turned off. +config SCSI_SCAN_ASYNC + bool "Asynchronous SCSI scanning" + depends on SCSI + help + The SCSI subsystem can probe for devices while the rest of the + system continues booting, and even probe devices on different + busses in parallel, leading to a significant speed-up. + If you have built SCSI as modules, enabling this option can + be a problem as the devices may not have been found by the + time your system expects them to have been. You can load the + scsi_wait_scan module to ensure that all scans have completed. + If you build your SCSI drivers into the kernel, then everything + will work fine if you say Y here. + + You can override this choice by specifying scsi_mod.scan="sync" + or "async" on the kernel's command line. + menu "SCSI Transports" depends on SCSI diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index aa1b1e0e9d22..d91d268dd331 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -89,7 +89,13 @@ module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(max_luns, "last scsi LUN (should be between 1 and 2^32-1)"); -static char scsi_scan_type[6] = "sync"; +#ifdef CONFIG_SCSI_SCAN_ASYNC +#define SCSI_SCAN_TYPE_DEFAULT "async" +#else +#define SCSI_SCAN_TYPE_DEFAULT "sync" +#endif + +static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT; module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO); MODULE_PARM_DESC(scan, "sync, async or none");