ata: ahci_brcm: Avoid writing to read-only registers

This commit makes use of the AHCI_HFLAG_YES_ALPM flag to prevent
the driver from writing to the read-only Host Capability register.

It also sets the AHCI_HFLAG_NO_WRITE_TO_RO flag to prevent the AHCI
library from writing to read-only registers.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Doug Berger 2017-06-21 16:20:14 -07:00 committed by Tejun Heo
parent 7fab72f85d
commit da8fa9cca5

View File

@ -39,7 +39,6 @@
#define PIODATA_ENDIAN_SHIFT 6
#define ENDIAN_SWAP_NONE 0
#define ENDIAN_SWAP_FULL 2
#define OVERRIDE_HWINIT BIT(16)
#define SATA_TOP_CTRL_TP_CTRL 0x8
#define SATA_TOP_CTRL_PHY_CTRL 0xc
#define SATA_TOP_CTRL_PHY_CTRL_1 0x0
@ -126,17 +125,13 @@ static inline void brcm_sata_writereg(u32 val, void __iomem *addr)
static void brcm_sata_alpm_init(struct ahci_host_priv *hpriv)
{
struct brcm_ahci_priv *priv = hpriv->plat_data;
u32 bus_ctrl, port_ctrl, host_caps;
u32 port_ctrl, host_caps;
int i;
/* Enable support for ALPM */
bus_ctrl = brcm_sata_readreg(priv->top_ctrl +
SATA_TOP_CTRL_BUS_CTRL);
brcm_sata_writereg(bus_ctrl | OVERRIDE_HWINIT,
priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL);
host_caps = readl(hpriv->mmio + HOST_CAP);
writel(host_caps | HOST_CAP_ALPM, hpriv->mmio);
brcm_sata_writereg(bus_ctrl, priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL);
if (!(host_caps & HOST_CAP_ALPM))
hpriv->flags |= AHCI_HFLAG_YES_ALPM;
/*
* Adjust timeout to allow PLL sufficient time to lock while waking
@ -360,6 +355,7 @@ static int brcm_ahci_probe(struct platform_device *pdev)
if (priv->quirks & BRCM_AHCI_QUIRK_NO_NCQ)
hpriv->flags |= AHCI_HFLAG_NO_NCQ;
hpriv->flags |= AHCI_HFLAG_NO_WRITE_TO_RO;
ret = ahci_platform_init_host(pdev, hpriv, &ahci_brcm_port_info,
&ahci_platform_sht);