On some kernels tuned for performance, you want to always favour
spin-up time versus power draw. This adds the ability to always favour
spin-up time by default (disabling Staggered Spin-up favours
performance, rather than power draw).
Regardless of whether this is enabled or disabled the
libahci.ignore_sss option will override any kernel config.
Signed-off-by: Eric Curtin <[email protected]>
---
drivers/ata/Kconfig | 15 +++++++++++++++
drivers/ata/libahci.c | 2 +-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 1c9f4fb2595d..36b11fbcf644 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -67,6 +67,21 @@ config ATA_FORCE
If unsure, say Y.
+config ATA_SSS
+ bool "Enable ATA Staggered Spin-up by default"
+ default y
+ help
+ This option denotes whether Staggered Spin-up capability on
+ storage controllers is used. Staggered Spin-up reduces
+ peak power draw, but decreases performance. If this config is
+ set to N, Staggered Spin-up capability will be ignored by
+ default.
+
+ This can be overridden by using the kernel argument
+ libahci.ignore_sss.
+
+ If unsure, say Y.
+
config ATA_ACPI
bool "ATA ACPI Support"
depends on ACPI
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index cf8c7fd59ada..b7b573d47fda 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -33,7 +33,7 @@
#include "libata.h"
static int ahci_skip_host_reset;
-int ahci_ignore_sss;
+int ahci_ignore_sss = !IS_ENABLED(CONFIG_ATA_SSS);
EXPORT_SYMBOL_GPL(ahci_ignore_sss);
module_param_named(skip_host_reset, ahci_skip_host_reset, int, 0444);
--
2.37.3
Err, no. We should not add config options for every damn default.
If you want to force it on CONFIG_CMDLINE is your friend.
The libahci.ignore_sss flag is something that is set by a number of
performance focused distros. The motivation behind this is to set
ignore_sss in a boolean fashion at compile time rather than depend on
cmdline parsing.
On Tue, 20 Sept 2022 at 07:56, Christoph Hellwig <[email protected]> wrote:
>
> Err, no. We should not add config options for every damn default.
> If you want to force it on CONFIG_CMDLINE is your friend.
>
On Tue, Sep 20, 2022 at 10:04:20AM +0100, Eric Curtin wrote:
> The libahci.ignore_sss flag is something that is set by a number of
> performance focused distros. The motivation behind this is to set
> ignore_sss in a boolean fashion at compile time rather than depend on
> cmdline parsing.
So set it in CONFIG_CMDLINE if you want it enabled at compile time.
The whole point of a built-in command line is to not add another
Kconfig option for every bloody option that someone wants a default
for.