target/linux/mvebu/patches-4.14/531-ATA-ahci_mvebu-pmp-stop-errata-226.patch

   1 From daa2e3bdbb0b3e691cf20a042350817310cb8cb5 Mon Sep 17 00:00:00 2001
   2 From: Evan Wang <xswang@marvell.com>
   3 Date: Fri, 13 Apr 2018 12:32:31 +0800
   4 Subject: [PATCH] ata: ahci: mvebu: override ahci_stop_engine for mvebu AHCI
   5
   6 There is an issue(Errata Ref#226) that the SATA can not be
   7 detected via SATA Port-MultiPlayer(PMP) with following
   8 error log:
   9   ata1.15: PMP product ID mismatch
  10   ata1.15: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
  11   ata1.15: Port Multiplier vendor mismatch '0x1b4b'!='0x0'
  12   ata1.15: PMP revalidation failed (errno=-19)
  13
  14 After debugging, the reason is found that the value Port-x
  15 FIS-based Switching Control(PxFBS@0x40) become wrong.
  16 According to design, the bits[11:8, 0] of register PxFBS
  17 are cleared when Port Command and Status (0x18) bit[0]
  18 changes its value from 1 to 0, i.e. falling edge of Port
  19 Command and Status bit[0] sends PULSE that resets PxFBS
  20 bits[11:8; 0].
  21 So it needs a mvebu SATA WA to save the port PxFBS register
  22 before PxCMD ST write and restore it afterwards.
  23
  24 This patch implements the WA in a separate function of
  25 ahci_mvebu_stop_engine to override ahci_stop_gngine.
  26
  27 Signed-off-by: Evan Wang <xswang@marvell.com>
  28 Cc: Ofer Heifetz <oferh@marvell.com>
  29 Cc: Tejun Heo <tj@kernel.org>
  30 Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
  31 Signed-off-by: Tejun Heo <tj@kernel.org>
  32 ---
  33  drivers/ata/ahci_mvebu.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
  34  1 file changed, 56 insertions(+)
  35
  36 diff --git a/drivers/ata/ahci_mvebu.c b/drivers/ata/ahci_mvebu.c
  37 index de7128d81e9cc..0045dacd814b4 100644
  38 --- a/drivers/ata/ahci_mvebu.c
  39 +++ b/drivers/ata/ahci_mvebu.c
  40 @@ -62,6 +62,60 @@ static void ahci_mvebu_regret_option(struct ahci_host_priv *hpriv)
  41         writel(0x80, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);
  42  }
  43
  44 +/**
  45 + * ahci_mvebu_stop_engine
  46 + *
  47 + * @ap:        Target ata port
  48 + *
  49 + * Errata Ref#226 - SATA Disk HOT swap issue when connected through
  50 + * Port Multiplier in FIS-based Switching mode.
  51 + *
  52 + * To avoid the issue, according to design, the bits[11:8, 0] of
  53 + * register PxFBS are cleared when Port Command and Status (0x18) bit[0]
  54 + * changes its value from 1 to 0, i.e. falling edge of Port
  55 + * Command and Status bit[0] sends PULSE that resets PxFBS
  56 + * bits[11:8; 0].
  57 + *
  58 + * This function is used to override function of "ahci_stop_engine"
  59 + * from libahci.c by adding the mvebu work around(WA) to save PxFBS
  60 + * value before the PxCMD ST write of 0, then restore PxFBS value.
  61 + *
  62 + * Return: 0 on success; Error code otherwise.
  63 + */
  64 +int ahci_mvebu_stop_engine(struct ata_port *ap)
  65 +{
  66 +       void __iomem *port_mmio = ahci_port_base(ap);
  67 +       u32 tmp, port_fbs;
  68 +
  69 +       tmp = readl(port_mmio + PORT_CMD);
  70 +
  71 +       /* check if the HBA is idle */
  72 +       if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
  73 +               return 0;
  74 +
  75 +       /* save the port PxFBS register for later restore */
  76 +       port_fbs = readl(port_mmio + PORT_FBS);
  77 +
  78 +       /* setting HBA to idle */
  79 +       tmp &= ~PORT_CMD_START;
  80 +       writel(tmp, port_mmio + PORT_CMD);
  81 +
  82 +       /*
  83 +        * bit #15 PxCMD signal doesn't clear PxFBS,
  84 +        * restore the PxFBS register right after clearing the PxCMD ST,
  85 +        * no need to wait for the PxCMD bit #15.
  86 +        */
  87 +       writel(port_fbs, port_mmio + PORT_FBS);
  88 +
  89 +       /* wait for engine to stop. This could be as long as 500 msec */
  90 +       tmp = ata_wait_register(ap, port_mmio + PORT_CMD,
  91 +                               PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1, 500);
  92 +       if (tmp & PORT_CMD_LIST_ON)
  93 +               return -EIO;
  94 +
  95 +       return 0;
  96 +}
  97 +
  98  #ifdef CONFIG_PM_SLEEP
  99  static int ahci_mvebu_suspend(struct platform_device *pdev, pm_message_t state)
 100  {
 101 @@ -112,6 +166,8 @@ static int ahci_mvebu_probe(struct platform_device *pdev)
 102         if (rc)
 103                 return rc;
 104
 105 +       hpriv->stop_engine = ahci_mvebu_stop_engine;
 106 +
 107         if (of_device_is_compatible(pdev->dev.of_node,
 108                                     "marvell,armada-380-ahci")) {
 109                 dram = mv_mbus_dram_info();
 110