From: Herve Codina <herve.codina@xxxxxxxxxxx> commit 075da584bae2da6a37428d59a477b6bdad430ac3 upstream. Some old IPs do not provide the hardware feature register. On these IPs, this register is read 0x00000000. In old driver version, this feature was handled but a regression came with the commit f10a6a3541b4 ("stmmac: rework get_hw_feature function"). Indeed, this commit removes the return value in dma->get_hw_feature(). This return value was used to indicate the validity of retrieved information and used later on in stmmac_hw_init() to override priv->plat data if this hardware feature were valid. This patch restores the return code in ->get_hw_feature() in order to indicate the hardware feature validity and override priv->plat data only if this hardware feature is valid. Fixes: f10a6a3541b4 ("stmmac: rework get_hw_feature function") Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 13 +++++++++++-- drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 6 ++++-- drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c | 6 ++++-- drivers/net/ethernet/stmicro/stmmac/hwif.h | 6 +++--- 4 files changed, 22 insertions(+), 9 deletions(-) --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c @@ -218,11 +218,18 @@ static void dwmac1000_dump_dma_regs(void readl(ioaddr + DMA_BUS_MODE + i * 4); } -static void dwmac1000_get_hw_feature(void __iomem *ioaddr, - struct dma_features *dma_cap) +static int dwmac1000_get_hw_feature(void __iomem *ioaddr, + struct dma_features *dma_cap) { u32 hw_cap = readl(ioaddr + DMA_HW_FEATURE); + if (!hw_cap) { + /* 0x00000000 is the value read on old hardware that does not + * implement this register + */ + return -EOPNOTSUPP; + } + dma_cap->mbps_10_100 = (hw_cap & DMA_HW_FEAT_MIISEL); dma_cap->mbps_1000 = (hw_cap & DMA_HW_FEAT_GMIISEL) >> 1; dma_cap->half_duplex = (hw_cap & DMA_HW_FEAT_HDSEL) >> 2; @@ -252,6 +259,8 @@ static void dwmac1000_get_hw_feature(voi dma_cap->number_tx_channel = (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22; /* Alternate (enhanced) DESC mode */ dma_cap->enh_desc = (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24; + + return 0; } static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt, --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c @@ -336,8 +336,8 @@ static void dwmac4_dma_tx_chan_op_mode(v writel(mtl_tx_op, ioaddr + MTL_CHAN_TX_OP_MODE(channel)); } -static void dwmac4_get_hw_feature(void __iomem *ioaddr, - struct dma_features *dma_cap) +static int dwmac4_get_hw_feature(void __iomem *ioaddr, + struct dma_features *dma_cap) { u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0); @@ -400,6 +400,8 @@ static void dwmac4_get_hw_feature(void _ dma_cap->frpbs = (hw_cap & GMAC_HW_FEAT_FRPBS) >> 11; dma_cap->frpsel = (hw_cap & GMAC_HW_FEAT_FRPSEL) >> 10; dma_cap->dvlan = (hw_cap & GMAC_HW_FEAT_DVLAN) >> 5; + + return 0; } /* Enable/disable TSO feature and set MSS */ --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c @@ -356,8 +356,8 @@ static int dwxgmac2_dma_interrupt(void _ return ret; } -static void dwxgmac2_get_hw_feature(void __iomem *ioaddr, - struct dma_features *dma_cap) +static int dwxgmac2_get_hw_feature(void __iomem *ioaddr, + struct dma_features *dma_cap) { u32 hw_cap; @@ -425,6 +425,8 @@ static void dwxgmac2_get_hw_feature(void dma_cap->frpes = (hw_cap & XGMAC_HWFEAT_FRPES) >> 11; dma_cap->frpbs = (hw_cap & XGMAC_HWFEAT_FRPPB) >> 9; dma_cap->frpsel = (hw_cap & XGMAC_HWFEAT_FRPSEL) >> 3; + + return 0; } static void dwxgmac2_rx_watchdog(void __iomem *ioaddr, u32 riwt, u32 nchan) --- a/drivers/net/ethernet/stmicro/stmmac/hwif.h +++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h @@ -196,8 +196,8 @@ struct stmmac_dma_ops { int (*dma_interrupt) (void __iomem *ioaddr, struct stmmac_extra_stats *x, u32 chan); /* If supported then get the optional core features */ - void (*get_hw_feature)(void __iomem *ioaddr, - struct dma_features *dma_cap); + int (*get_hw_feature)(void __iomem *ioaddr, + struct dma_features *dma_cap); /* Program the HW RX Watchdog */ void (*rx_watchdog)(void __iomem *ioaddr, u32 riwt, u32 number_chan); void (*set_tx_ring_len)(void __iomem *ioaddr, u32 len, u32 chan); @@ -247,7 +247,7 @@ struct stmmac_dma_ops { #define stmmac_dma_interrupt_status(__priv, __args...) \ stmmac_do_callback(__priv, dma, dma_interrupt, __args) #define stmmac_get_hw_feature(__priv, __args...) \ - stmmac_do_void_callback(__priv, dma, get_hw_feature, __args) + stmmac_do_callback(__priv, dma, get_hw_feature, __args) #define stmmac_rx_watchdog(__priv, __args...) \ stmmac_do_void_callback(__priv, dma, rx_watchdog, __args) #define stmmac_set_tx_ring_len(__priv, __args...) \