FAILED: patch "[PATCH] net: stmmac: fix get_hw_feature() on old hardware" failed to apply to 4.19-stable tree

PATCH [email protected] 1 participant 1 message Oct 18, 2021

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Network drivers Stable branch Arm STM32 stmmac Ethernet driver

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2021-10-18 11:04 UTC #0 lore raw

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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 075da584bae2da6a37428d59a477b6bdad430ac3 Mon Sep 17 00:00:00 2001
From: Herve Codina <[email protected]>
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 <[email protected]>

Signed-off-by David S. Miller <[email protected]>

drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c +11 -2

index 90383abafa66..f5581db0ba9b 100644
@@ -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,

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c +4 -2

index 5be8e6a631d9..d99fa028c646 100644
@@ -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 */

drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c +4 -2

index 906e985441a9..5e98355f422b 100644
@@ -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)

drivers/net/ethernet/stmicro/stmmac/hwif.h +3 -3

index 6dc1c98ebec8..fe2660d5694d 100644
@@ -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...) \