On 9/27/22 04:51, Maciej S. Szmigiero wrote: > From: "Maciej S. Szmigiero" <maciej.szmigiero@xxxxxxxxxx> > > Currently, if one wants to make use of FUA support in libata it is > necessary to provide an explicit kernel command line parameter in order to > enable it (for drives that report such support). > > In terms of Git archaeology: FUA support was enabled by default in early > libata versions but was disabled soon after. > Since then there were a few attempts to enable this support by default: > [1] (for NCQ drives only), [2] (for all drives). > However, the second change had to be reverted after a report came of > an incompatibility with the HDD in 2011 Mac Mini. > > Enabling FUA avoids having to emulate it by issuing an extra drive cache > flush for every request that have this flag set. > Since FUA support is required by the ATA/ATAPI spec for any drive that > supports LBA48 and so these days should be pretty widespread let's provide > an ability to enable it by default in Kconfig. This can be done by adding "libata.fua=1" to the CONFIG_CMDLINE option. So I do not see the need to add yet another config option. Patch 1 looks good. I will queue it up once rc1 is out. > > [1]: https://lore.kernel.org/lkml/45CFFF82.4030301@xxxxxxx/ > [2]: https://lore.kernel.org/lkml/1336447443-4685-1-git-send-email-wenqing.lz@xxxxxxxxxx/ > > Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@xxxxxxxxxx> > --- > drivers/ata/Kconfig | 15 +++++++++++++++ > drivers/ata/libata-core.c | 5 +++-- > 2 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig > index 36833a8629980..fd39bb22963a3 100644 > --- a/drivers/ata/Kconfig > +++ b/drivers/ata/Kconfig > @@ -102,6 +102,21 @@ config SATA_PMP > This option adds support for SATA Port Multipliers > (the SATA version of an ethernet hub, or SAS expander). > > +config ATA_FUA > + bool "ATA FUA support" > + help > + Enables Forced Unit Access (FUA) support by default for drives that > + have it. > + Otherwise the FUA flag has to be emulated by flushing the drive cache. > + > + Regardless of this option, you can enable or disable such support at > + kernel boot time by providing libata.fua=1 or libata.fua=0 kernel > + command line parameter. > + > + If building a kernel for yourself, say Y. > + If building a kernel for a distro that's supposed to run out of the > + box on old and broken hardware say N. > + > if HAS_DMA > > comment "Controllers with non-SFF native interface" > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c > index b322006c85806..941836c4b5eda 100644 > --- a/drivers/ata/libata-core.c > +++ b/drivers/ata/libata-core.c > @@ -127,9 +127,10 @@ int atapi_passthru16 = 1; > module_param(atapi_passthru16, int, 0444); > MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); > > -int libata_fua = 0; > +int libata_fua = IS_ENABLED(CONFIG_ATA_FUA); > module_param_named(fua, libata_fua, int, 0644); > -MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); > +MODULE_PARM_DESC(fua, > + "FUA support (0=off, 1=on), default " __stringify(IS_ENABLED(CONFIG_ATA_FUA))); > > static int ata_ignore_hpa; > module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644); -- Damien Le Moal Western Digital Research
