The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 075da584bae2da6a37428d59a477b6bdad430ac3 Mon Sep 17 00:00:00 2001
From: Herve Codina herve.codina@bootlin.com Date: Fri, 8 Oct 2021 12:34:37 +0200 Subject: [PATCH] net: stmmac: fix get_hw_feature() on old hardware
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@bootlin.com Signed-off-by: David S. Miller davem@davemloft.net
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c index 90383abafa66..f5581db0ba9b 100644 --- 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 __iomem *ioaddr, u32 *reg_space) 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(void __iomem *ioaddr, 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, diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c index 5be8e6a631d9..d99fa028c646 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c @@ -347,8 +347,8 @@ static void dwmac4_dma_tx_chan_op_mode(void __iomem *ioaddr, int mode, 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);
@@ -437,6 +437,8 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr, 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 */ diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c index 906e985441a9..5e98355f422b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c @@ -371,8 +371,8 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr, 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;
@@ -445,6 +445,8 @@ static void dwxgmac2_get_hw_feature(void __iomem *ioaddr, 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 queue) diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h index 6dc1c98ebec8..fe2660d5694d 100644 --- a/drivers/net/ethernet/stmicro/stmmac/hwif.h +++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h @@ -203,8 +203,8 @@ struct stmmac_dma_ops { int (*dma_interrupt) (void __iomem *ioaddr, struct stmmac_extra_stats *x, u32 chan, u32 dir); /* 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 queue); void (*set_tx_ring_len)(void __iomem *ioaddr, u32 len, u32 chan); @@ -255,7 +255,7 @@ 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...) \