From: Doug Berger <opendmb@gmail.com>
To: tj@kernel.org
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
Doug Berger <opendmb@gmail.com>
Subject: [PATCH 3/3] ata: ahci_brcm: Avoid writing to read-only registers
Date: Wed, 21 Jun 2017 16:20:14 -0700 [thread overview]
Message-ID: <20170621232014.27790-4-opendmb@gmail.com> (raw)
In-Reply-To: <20170621232014.27790-1-opendmb@gmail.com>
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>
---
drivers/ata/ahci_brcm.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/ata/ahci_brcm.c b/drivers/ata/ahci_brcm.c
index 6f8a7341fa08..5936d1679bf3 100644
--- a/drivers/ata/ahci_brcm.c
+++ b/drivers/ata/ahci_brcm.c
@@ -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);
--
2.13.0
next prev parent reply other threads:[~2017-06-21 23:20 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-21 23:20 [PATCH 0/3] libata: prevent writes to read-only registers Doug Berger
2017-06-21 23:20 ` [PATCH 1/3] libata: Add the AHCI_HFLAG_YES_ALPM flag Doug Berger
2017-06-21 23:20 ` [PATCH 2/3] libata: Add the AHCI_HFLAG_NO_WRITE_TO_RO flag Doug Berger
2017-06-21 23:20 ` Doug Berger [this message]
2017-06-22 20:13 ` [PATCH 0/3] libata: prevent writes to read-only registers Tejun Heo
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