ata: ahci_brcm: Avoid clobbering SATA_TOP_CTRL_BUS_CTRL

We are doing a blind write to SATA_TOP_CTRL_BUS_CTRL to set the system
endian, but in doing so, we are also overwriting other bits, such as the
SATA_SCB_BURST_SIZE and SATA_FIFO_SIZE bits, which impact performance.
Do a read/modify/write so we keep the default values.

While we are at it, we also greatly simplify the logic and just leave
the NSP specific bit settings, instead of having a completely different
sequence.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ata/ahci_brcm.c b/drivers/ata/ahci_brcm.c
index 5936d16..ad3b882 100644 (file)
--- a/drivers/ata/ahci_brcm.c
+++ b/drivers/ata/ahci_brcm.c
@@ -70,6 +70,13 @@
        (DATA_ENDIAN << DMADESC_ENDIAN_SHIFT) |         \
        (MMIO_ENDIAN << MMIO_ENDIAN_SHIFT))
 
+#define BUS_CTRL_ENDIAN_NSP_CONF                       \
+       (0x02 << DMADATA_ENDIAN_SHIFT | 0x02 << DMADESC_ENDIAN_SHIFT)
+
+#define BUS_CTRL_ENDIAN_CONF_MASK                      \
+       (0x3 << MMIO_ENDIAN_SHIFT | 0x3 << DMADESC_ENDIAN_SHIFT |       \
+        0x3 << DMADATA_ENDIAN_SHIFT | 0x3 << PIODATA_ENDIAN_SHIFT)
+
 enum brcm_ahci_version {
        BRCM_SATA_BCM7425 = 1,
        BRCM_SATA_BCM7445,
@@ -250,18 +257,16 @@ static u32 brcm_ahci_get_portmask(struct platform_device *pdev,
 static void brcm_sata_init(struct brcm_ahci_priv *priv)
 {
        void __iomem *ctrl = priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL;
+       u32 data;
 
        /* Configure endianness */
-       if (priv->version ==  BRCM_SATA_NSP) {
-               u32 data = brcm_sata_readreg(ctrl);
-
-               data &= ~((0x03 << DMADATA_ENDIAN_SHIFT) |
-                       (0x03 << DMADESC_ENDIAN_SHIFT));
-               data |= (0x02 << DMADATA_ENDIAN_SHIFT) |
-                       (0x02 << DMADESC_ENDIAN_SHIFT);
-               brcm_sata_writereg(data, ctrl);
-       } else
-               brcm_sata_writereg(BUS_CTRL_ENDIAN_CONF, ctrl);
+       data = brcm_sata_readreg(ctrl);
+       data &= ~BUS_CTRL_ENDIAN_CONF_MASK;
+       if (priv->version == BRCM_SATA_NSP)
+               data |= BUS_CTRL_ENDIAN_NSP_CONF;
+       else
+               data |= BUS_CTRL_ENDIAN_CONF;
+       brcm_sata_writereg(data, ctrl);
 }
 
 #ifdef CONFIG_PM_SLEEP