On 9/5/23 21:49, Niklas Cassel wrote: > From: Niklas Cassel <niklas.cassel@xxxxxxx> > > The target LPM policy can be set using either a Kconfig or a kernel module > parameter. > > However, if the board type is set to anything but board_ahci_low_power, > then the LPM policy will overridden and set to ATA_LPM_UNKNOWN. > > Additionally, if the default suspend is suspend to idle, depending on the > hardware capabilities of the HBA, ahci_update_initial_lpm_policy() might > override the LPM policy to either ATA_LPM_MIN_POWER_WITH_PARTIAL or > ATA_LPM_MIN_POWER. > > All this means that it is very hard to know which LPM policy a user will > actually be using on a given system. > > In order to make it easier to debug LPM related issues, print the LPM > policy on boot. > > One common LPM related issue is that the device fails to link up. > Because of that, we cannot add this print to ata_dev_configure(), as that > function is only called after a successful link up. Instead, add the info > using ata_port_desc(). The port description is printed once during boot. > > Before changes: > ata1: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780100 irq 170 > ata2: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780180 irq 170 > > After changes: > ata1: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780100 lpm-pol 4 irq 170 > ata2: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780180 lpm-pol 4 irq 170 Looks good, but maybe print the lpm-pol value at the end, after the IRQ number, to preserve the beginning of the message as it was before. Or even better: why not print the LPM modes supported by the port and the target lpm policy (lpm-pol) as a new ata_port_info() message right after the port desc message ? > > Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxx> > --- > drivers/ata/ahci.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c > index abb5911c9d09..541f6ec7f395 100644 > --- a/drivers/ata/ahci.c > +++ b/drivers/ata/ahci.c > @@ -1898,6 +1898,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) > ap->em_message_type = hpriv->em_msg_type; > > ahci_update_initial_lpm_policy(ap, hpriv); > + ata_port_desc(ap, "lpm-pol %d", ap->target_lpm_policy); > > /* disabled/not-implemented port */ > if (!(hpriv->port_map & (1 << i))) -- Damien Le Moal Western Digital Research
