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ata: ahci: mvebu: override ahci_stop_engine for mvebu AHCI 

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>
Cc: Ofer Heifetz <oferh@marvell.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Evan Wang 2018-04-13 12:32:31 +08:00 committed by Tejun Heo
parent fa89f53bd7
commit daa2e3bdbb
1 changed files with 56 additions and 0 deletions
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56
drivers/ata/ahci_mvebu.c
View File

@ -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();