From: Evan Wang xswang@marvell.com

There is an issue(Errata Ref#226) that the SATA can not be detected via SATA Port-MultiPlayer(PMP) with following error log: ata1.15: PMP product ID mismatch ata1.15: SATA link up 6.0 Gbps (SStatus 133 SControl 300) ata1.15: Port Multiplier vendor mismatch '0x1b4b'!='0x0' ata1.15: PMP revalidation failed (errno=-19)

After debugging, the reason is found that the value Port-x FIS-based Switching Control(PxFBS@0x40) become wrong. According to design, the bits[11:8, 0] of register PxFBS are cleared when Port Command and Status (0x18) bit[0] changes its value from 1 to 0, i.e. falling edge of Port Command and Status bit[0] sends PULSE that resets PxFBS bits[11:8; 0]. So it needs a mvebu SATA WA to save the port PxFBS register before PxCMD ST write and restore it afterwards.

This patch implements the WA in a separate function of ahci_mvebu_stop_engine to override ahci_stop_gngine.

Signed-off-by: Evan Wang xswang@marvell.com Suggested-by: Ofer Heifetz oferh@marvell.com Cc: Tejun Heo tj@kernel.org Cc: Thomas Petazzoni thomas.petazzoni@bootlin.com Cc: stable@vger.kernel.org --- drivers/ata/ahci_mvebu.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)

diff --git a/drivers/ata/ahci_mvebu.c b/drivers/ata/ahci_mvebu.c index de7128d..0045dac 100644 --- a/drivers/ata/ahci_mvebu.c +++ b/drivers/ata/ahci_mvebu.c @@ -62,6 +62,60 @@ static void ahci_mvebu_regret_option(struct ahci_host_priv *hpriv) writel(0x80, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA); }

+/** + * ahci_mvebu_stop_engine + * + * @ap: Target ata port + * + * Errata Ref#226 - SATA Disk HOT swap issue when connected through + * Port Multiplier in FIS-based Switching mode. + * + * To avoid the issue, according to design, the bits[11:8, 0] of + * register PxFBS are cleared when Port Command and Status (0x18) bit[0] + * changes its value from 1 to 0, i.e. falling edge of Port + * Command and Status bit[0] sends PULSE that resets PxFBS + * bits[11:8; 0]. + * + * This function is used to override function of "ahci_stop_engine" + * from libahci.c by adding the mvebu work around(WA) to save PxFBS + * value before the PxCMD ST write of 0, then restore PxFBS value. + * + * Return: 0 on success; Error code otherwise. + */ +int ahci_mvebu_stop_engine(struct ata_port *ap) +{ + void __iomem *port_mmio = ahci_port_base(ap); + u32 tmp, port_fbs; + + tmp = readl(port_mmio + PORT_CMD); + + /* check if the HBA is idle */ + if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0) + return 0; + + /* save the port PxFBS register for later restore */ + port_fbs = readl(port_mmio + PORT_FBS); + + /* setting HBA to idle */ + tmp &= ~PORT_CMD_START; + writel(tmp, port_mmio + PORT_CMD); + + /* + * bit #15 PxCMD signal doesn't clear PxFBS, + * restore the PxFBS register right after clearing the PxCMD ST, + * no need to wait for the PxCMD bit #15. + */ + writel(port_fbs, port_mmio + PORT_FBS); + + /* wait for engine to stop. This could be as long as 500 msec */ + tmp = ata_wait_register(ap, port_mmio + PORT_CMD, + PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1, 500); + if (tmp & PORT_CMD_LIST_ON) + return -EIO; + + return 0; +} + #ifdef CONFIG_PM_SLEEP static int ahci_mvebu_suspend(struct platform_device *pdev, pm_message_t state) { @@ -112,6 +166,8 @@ static int ahci_mvebu_probe(struct platform_device *pdev) if (rc) return rc;

+ hpriv->stop_engine = ahci_mvebu_stop_engine; + if (of_device_is_compatible(pdev->dev.of_node, "marvell,armada-380-ahci")) { dram = mv_mbus_dram_info();