From 7b05f5e027b81cd3a9a41c6c6d3fe09c72fa93f6 Mon Sep 17 00:00:00 2001 From: Simon Kagstrom Date: Wed, 8 Jul 2009 13:03:18 +0200 Subject: [PATCH] arm: Kirkwood: Fix compiler optimization bug for kwgbe_send kwgbe_send/recv both have loops waiting for the hardware to set a bit. GCC 4.3.3 cleverly optimizes the send case to ... a while(1); loop. This patch uses readl to force a read from device memory. Other volatile accesses have also been replaced with readl/writel where appropriate (as per suggestions on the U-boot mailing list). Signed-off-by: Simon Kagstrom Signed-off-by: Ben Warren --- drivers/net/kirkwood_egiga.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/net/kirkwood_egiga.c b/drivers/net/kirkwood_egiga.c index 3c5db19cb0..77c7a840cf 100644 --- a/drivers/net/kirkwood_egiga.c +++ b/drivers/net/kirkwood_egiga.c @@ -49,7 +49,7 @@ static int smi_reg_read(char *devname, u8 phy_adr, u8 reg_ofs, u16 * data) struct kwgbe_device *dkwgbe = to_dkwgbe(dev); struct kwgbe_registers *regs = dkwgbe->regs; u32 smi_reg; - volatile u32 timeout; + u32 timeout; /* Phyadr read request */ if (phy_adr == 0xEE && reg_ofs == 0xEE) { @@ -124,7 +124,7 @@ static int smi_reg_write(char *devname, u8 phy_adr, u8 reg_ofs, u16 data) struct kwgbe_device *dkwgbe = to_dkwgbe(dev); struct kwgbe_registers *regs = dkwgbe->regs; u32 smi_reg; - volatile u32 timeout; + u32 timeout; /* Phyadr write request*/ if (phy_adr == 0xEE && reg_ofs == 0xEE) { @@ -370,7 +370,7 @@ static void port_uc_addr_set(struct kwgbe_registers *regs, u8 * p_addr) */ static void kwgbe_init_rx_desc_ring(struct kwgbe_device *dkwgbe) { - volatile struct kwgbe_rxdesc *p_rx_desc; + struct kwgbe_rxdesc *p_rx_desc; int i; /* initialize the Rx descriptors ring */ @@ -487,6 +487,7 @@ static int kwgbe_send(struct eth_device *dev, volatile void *dataptr, struct kwgbe_device *dkwgbe = to_dkwgbe(dev); struct kwgbe_registers *regs = dkwgbe->regs; struct kwgbe_txdesc *p_txdesc = dkwgbe->p_txdesc; + u32 cmd_sts; if ((u32) dataptr & 0x07) { printf("Err..(%s) xmit dataptr not 64bit aligned\n", @@ -507,21 +508,24 @@ static int kwgbe_send(struct eth_device *dev, volatile void *dataptr, /* * wait for packet xmit completion */ - while (p_txdesc->cmd_sts & KWGBE_BUFFER_OWNED_BY_DMA) { + cmd_sts = readl(&p_txdesc->cmd_sts); + while (cmd_sts & KWGBE_BUFFER_OWNED_BY_DMA) { /* return fail if error is detected */ - if (p_txdesc->cmd_sts & (KWGBE_UR_ERROR | KWGBE_RL_ERROR)) { + if (cmd_sts & (KWGBE_UR_ERROR | KWGBE_RL_ERROR)) { printf("Err..(%s) in xmit packet\n", __FUNCTION__); return -1; } + cmd_sts = readl(&p_txdesc->cmd_sts); }; return 0; } static int kwgbe_recv(struct eth_device *dev) { - volatile struct kwgbe_device *dkwgbe = to_dkwgbe(dev); - volatile struct kwgbe_rxdesc *p_rxdesc_curr = dkwgbe->p_rxdesc_curr; - volatile u32 timeout = 0; + struct kwgbe_device *dkwgbe = to_dkwgbe(dev); + struct kwgbe_rxdesc *p_rxdesc_curr = dkwgbe->p_rxdesc_curr; + u32 cmd_sts; + u32 timeout = 0; /* wait untill rx packet available or timeout */ do { @@ -531,7 +535,7 @@ static int kwgbe_recv(struct eth_device *dev) debug("%s time out...\n", __FUNCTION__); return -1; } - } while (p_rxdesc_curr->cmd_sts & KWGBE_BUFFER_OWNED_BY_DMA); + } while (readl(&p_rxdesc_curr->cmd_sts) & KWGBE_BUFFER_OWNED_BY_DMA); if (p_rxdesc_curr->byte_cnt != 0) { debug("%s: Received %d byte Packet @ 0x%x (cmd_sts= %08x)\n", @@ -545,14 +549,16 @@ static int kwgbe_recv(struct eth_device *dev) * OR the error summary bit is on, * the packets needs to be dropeed. */ - if ((p_rxdesc_curr->cmd_sts & + cmd_sts = readl(&p_rxdesc_curr->cmd_sts); + + if ((cmd_sts & (KWGBE_RX_FIRST_DESC | KWGBE_RX_LAST_DESC)) != (KWGBE_RX_FIRST_DESC | KWGBE_RX_LAST_DESC)) { printf("Err..(%s) Dropping packet spread on" " multiple descriptors\n", __FUNCTION__); - } else if (p_rxdesc_curr->cmd_sts & KWGBE_ERROR_SUMMARY) { + } else if (cmd_sts & KWGBE_ERROR_SUMMARY) { printf("Err..(%s) Dropping packet with errors\n", __FUNCTION__); @@ -574,7 +580,8 @@ static int kwgbe_recv(struct eth_device *dev) p_rxdesc_curr->buf_size = PKTSIZE_ALIGN; p_rxdesc_curr->byte_cnt = 0; - dkwgbe->p_rxdesc_curr = p_rxdesc_curr->nxtdesc_p; + writel((unsigned)p_rxdesc_curr->nxtdesc_p, &dkwgbe->p_rxdesc_curr); + return 0; } -- 2.25.1