Messages in this thread Patch in this message | | | Date | Mon, 11 Aug 2008 15:36:41 -0700 | From | Arjan van de Ven <> | Subject | [patch 1/2] fastboot: Add a module parameter to skip probing of specific ports |
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From: Kristen Accardi <kristen.c.accardi@intel.com> Subject: [PATCH] libata: Add a module parameter to skip probing of specific ports
Port probing by libata can easily take 10% or more of the kernel boot time (2%+ of total). For cases where one knows there is nothing connected to certain ports (for example on netbooks) this is a waste of boot time.
This patch adds a module parameter that allows the admin to specify to skip ports (specified by a bitmask) and recoup this boot time. This capability is potentially also useful to get systems to boot for cases where port-probing on a certain ports causes crashes.
A follow-on patch will add the capability to use DMI identification to automate this for certain known systems.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> --- drivers/ata/libata-core.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 5ba96c5..831a8ca 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -148,6 +148,10 @@ static int ata_probe_timeout; module_param(ata_probe_timeout, int, 0444); MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)"); +static int libata_disable_ports; +module_param_named(disable_ports, libata_disable_ports, int, 0444); +MODULE_PARM_DESC(disable_ports, "Disable specified ports (as bitmask) at boot time"); + int libata_noacpi = 0; module_param_named(noacpi, libata_noacpi, int, 0444); MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set"); @@ -5651,6 +5655,13 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht) for (i = 0; i < host->n_ports; i++) { struct ata_port *ap = host->ports[i]; + /* + * check if the port is specified as 'to disable' by either + * a module parameter or a DMI match + */ + if (libata_disable_ports & (1 << ap->port_no)) + continue; + /* probe */ if (ap->ops->error_handler) { struct ata_eh_info *ehi = &ap->link.eh_info; -- 1.5.5.1
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