On some platforms, the macb integration does not use the USRIO
register to configure the (R)MII port and clocks.
When the register is not implemented and the MACB error signal
is connected to the bus error, reading or writing to the USRIO
register can trigger some Imprecise External Aborts on ARM platforms.
Signed-off-by: Neil Armstrong <narmstr...@baylibre.com>
---
drivers/net/ethernet/cadence/macb.c | 27 +++++++++++++++------------
drivers/net/ethernet/cadence/macb.h | 1 +
2 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/cadence/macb.c
b/drivers/net/ethernet/cadence/macb.c
index 169059c..9325140 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -2122,7 +2122,8 @@ static void macb_get_regs(struct net_device *dev, struct
ethtool_regs *regs,
regs_buff[10] = macb_tx_dma(&bp->queues[0], tail);
regs_buff[11] = macb_tx_dma(&bp->queues[0], head);
- regs_buff[12] = macb_or_gem_readl(bp, USRIO);
+ if (!(bp->caps & MACB_CAPS_USRIO_DISABLED))
+ regs_buff[12] = macb_or_gem_readl(bp, USRIO);
if (macb_is_gem(bp)) {
regs_buff[13] = gem_readl(bp, DMACFG);
}
@@ -2401,19 +2402,21 @@ static int macb_init(struct platform_device *pdev)
dev->hw_features &= ~NETIF_F_SG;
dev->features = dev->hw_features;
- val = 0;
- if (bp->phy_interface == PHY_INTERFACE_MODE_RGMII)
- val = GEM_BIT(RGMII);
- else if (bp->phy_interface == PHY_INTERFACE_MODE_RMII &&
- (bp->caps & MACB_CAPS_USRIO_DEFAULT_IS_MII))
- val = MACB_BIT(RMII);
- else if (!(bp->caps & MACB_CAPS_USRIO_DEFAULT_IS_MII))
- val = MACB_BIT(MII);
+ if (!(bp->caps & MACB_CAPS_USRIO_DISABLED)) {
+ val = 0;
+ if (bp->phy_interface == PHY_INTERFACE_MODE_RGMII)
+ val = GEM_BIT(RGMII);
+ else if (bp->phy_interface == PHY_INTERFACE_MODE_RMII &&
+ (bp->caps & MACB_CAPS_USRIO_DEFAULT_IS_MII))
+ val = MACB_BIT(RMII);
+ else if (!(bp->caps & MACB_CAPS_USRIO_DEFAULT_IS_MII))
+ val = MACB_BIT(MII);
- if (bp->caps & MACB_CAPS_USRIO_HAS_CLKEN)
- val |= MACB_BIT(CLKEN);
+ if (bp->caps & MACB_CAPS_USRIO_HAS_CLKEN)
+ val |= MACB_BIT(CLKEN);
- macb_or_gem_writel(bp, USRIO, val);
+ macb_or_gem_writel(bp, USRIO, val);
+ }
/* Set MII management clock divider */
val = macb_mdc_clk_div(bp);
diff --git a/drivers/net/ethernet/cadence/macb.h
b/drivers/net/ethernet/cadence/macb.h
index d83b0db..65ea049 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -400,6 +400,7 @@
#define MACB_CAPS_USRIO_HAS_CLKEN 0x00000002
#define MACB_CAPS_USRIO_DEFAULT_IS_MII 0x00000004
#define MACB_CAPS_NO_GIGABIT_HALF 0x00000008
+#define MACB_CAPS_USRIO_DISABLED 0x00000010
#define MACB_CAPS_FIFO_MODE 0x10000000
#define MACB_CAPS_GIGABIT_MODE_AVAILABLE 0x20000000
#define MACB_CAPS_SG_DISABLED 0x40000000
--
1.9.1
--
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