On Tue, Feb 06, 2024 at 10:13:41PM +0100, Niklas Cassel wrote: > The series is based on top of: > https://git.kernel.org/pub/scm/linux/kernel/git/libata/linux.git/log/?h=for-next > > > Hello all, > > This revives a patch sent out almost two years ago from Mario Limonciello: > https://lore.kernel.org/linux-ide/20220524170508.563-1-mario.limonciello@xxxxxxx/T/#u > > The reason why we did not merge it back then, is because LPM and hotplug > events are mutually exclusive. > > The difference with this series compared to what was sent out back then: > I've added a patch that checks if the port is external, i.e. either > hotplug capable or eSATA. For external ports, we never enable LPM, as > that will break hotplug. > > For ports that do not advertise themselves as external (typically laptops), > we set the LPM policy as requested. > > This matches how Microsoft Windows does things, see: > https://studylib.net/doc/10034428/esata---microsoft-center > > Thanks to Werner Fischer for suggesting something like this at last year's > ALPSS conference. > > There might of course be some platform firmware that e.g. incorrectly marks > its port as internal, even though it is external, but if we find any such > platforms we will need to deal with them using quirks. > > > Also note that we even if the user requested a certain policy, there is > no guarantee that he will get all the features for that policy, see: > https://github.com/torvalds/linux/blob/master/drivers/ata/libata-sata.c#L403-L414 > > However, I'd rather we not try to map all the combinations of > partial/slumber/devsleep in to a single policy represented by a single > integer, thus I do not try to "change" the requested policy. > The user will get all the features that are included in the requested > policy AND supported by the HBA. > > Another difference (compared to an earlier version of Mario's series) > is that we do not try to change the default CONFIG_SATA_MOBILE_LPM_POLICY > value from 0 to 3, it will continue to be 0. > If you really don't want LPM even if your HBA supports it, and your port > is internal, one option is to leave the Kconfig set to the default value. > > Damien: considering that the Intel VMD + ahci_intel_pcs_quirk() bug turned > out to have nothing to do with LPM, it was simply the fact that the > ahci_intel_pcs_quirk() was only applied if there was an explicit entry in > ahci_pci_tbl. So since that bug is totally unrelated to LPM, I no longer > think that this series need to wait for a fix for that bug. > > > Link to v1: > https://lore.kernel.org/linux-ide/20240201161507.1147521-1-cassel@xxxxxxxxxx/ > > Changes since v1: > -Picked up tags from Damien. > -Moved the comment in front of ahci_mark_external_port() to inside the > function. > -Modified the comment in patch 4/5 to more clearly state hotplug removal > events. > -Rewrote the commit message for patch 4/5 to be more detailed. > > > Kind regards, > Niklas > > > Mario Limonciello (1): > ata: ahci: Drop low power policy board type > > Niklas Cassel (4): > ata: ahci: move marking of external port earlier > ata: ahci: a hotplug capable port is an external port > ata: ahci: drop hpriv param from ahci_update_initial_lpm_policy() > ata: ahci: do not enable LPM on external ports > > drivers/ata/Kconfig | 5 +- > drivers/ata/ahci.c | 135 +++++++++++++++++++++++------------------- > drivers/ata/ahci.h | 9 +-- > drivers/ata/libahci.c | 7 --- > 4 files changed, 78 insertions(+), 78 deletions(-) > > -- > 2.43.0 > Applied: https://git.kernel.org/pub/scm/linux/kernel/git/libata/linux.git/log/?h=for-6.9
