On Thu, 2016-01-07 at 14:53 -0600, Brijesh Singh wrote: > AMD Seattle SATA controller mostly conforms to AHCI interface with some > special register to control SGPIO interface. In the case of an AHCI > controller, the SGPIO feature is ideally implemented using the > "Enclosure Management" register of the AHCI controller, but those > registeres are not implemented in the Seattle SoC. Instead SoC > (Rev B0 onwards) provides a 32-bit SGPIO control register which should > be programmed to control the activity, locate and fault LEDs. trivia: > diff --git a/drivers/ata/ahci_seattle.c b/drivers/ata/ahci_seattle.c [] > +static ssize_t seattle_transmit_led_message(struct ata_port *ap, u32 state, > + ssize_t size) > +{ > + struct ahci_host_priv *hpriv = ap->host->private_data; > + struct ahci_port_priv *pp = ap->private_data; > + struct seattle_plat_data *plat_data = hpriv->plat_data; > + unsigned long flags; > + int pmp; > + struct ahci_em_priv *emp; > + u32 val; > + > + /* get the slot number from the message */ > + pmp = (state & EM_MSG_LED_PMP_SLOT) >> 8; > + if (pmp < EM_MAX_SLOTS) > + emp = &pp->em_priv[pmp]; > + else > + return -EINVAL; This is generally done using a inverted test that returns immediately if (pmp >= EMP_MAX_SLOTS) return -EINVAL; emp = &pp->em_priv[pmp]; -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html