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605c357bb4
Commit210dce5f"ARM: ep93xx: properly wait for UART FIFO to be empty" Removed the timeout loop while waiting for the uart transmit fifo to empty. Some bootloaders leave the uart in a state where there might be bytes in the uart that are not transmitted when execution is handed over to the kernel. This results in a deadlocked system while waiting for the fifo to empty. Add back the timeout wait to prevent the deadlock. Increase the wait time to hopefully prevent the decompressor corruption that lead to commit210dce5f. This corruption was probably due to a slow uart baudrate. The 10* increase in the wait time should be enough for all cases. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ryan Mallon <rmallon@gmail.com>
93 lines
2.2 KiB
C
93 lines
2.2 KiB
C
/*
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* arch/arm/mach-ep93xx/include/mach/uncompress.h
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*
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* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#include <mach/ep93xx-regs.h>
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static unsigned char __raw_readb(unsigned int ptr)
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{
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return *((volatile unsigned char *)ptr);
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}
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static unsigned int __raw_readl(unsigned int ptr)
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{
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return *((volatile unsigned int *)ptr);
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}
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static void __raw_writeb(unsigned char value, unsigned int ptr)
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{
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*((volatile unsigned char *)ptr) = value;
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}
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static void __raw_writel(unsigned int value, unsigned int ptr)
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{
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*((volatile unsigned int *)ptr) = value;
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}
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#if defined(CONFIG_EP93XX_EARLY_UART1)
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#define UART_BASE EP93XX_UART1_PHYS_BASE
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#elif defined(CONFIG_EP93XX_EARLY_UART2)
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#define UART_BASE EP93XX_UART2_PHYS_BASE
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#elif defined(CONFIG_EP93XX_EARLY_UART3)
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#define UART_BASE EP93XX_UART3_PHYS_BASE
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#else
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#define UART_BASE EP93XX_UART1_PHYS_BASE
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#endif
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#define PHYS_UART_DATA (UART_BASE + 0x00)
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#define PHYS_UART_FLAG (UART_BASE + 0x18)
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#define UART_FLAG_TXFF 0x20
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static inline void putc(int c)
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{
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int i;
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for (i = 0; i < 10000; i++) {
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/* Transmit fifo not full? */
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if (!(__raw_readb(PHYS_UART_FLAG) & UART_FLAG_TXFF))
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break;
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}
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__raw_writeb(c, PHYS_UART_DATA);
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}
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static inline void flush(void)
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{
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}
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/*
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* Some bootloaders don't turn off DMA from the ethernet MAC before
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* jumping to linux, which means that we might end up with bits of RX
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* status and packet data scribbled over the uncompressed kernel image.
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* Work around this by resetting the ethernet MAC before we uncompress.
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*/
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#define PHYS_ETH_SELF_CTL 0x80010020
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#define ETH_SELF_CTL_RESET 0x00000001
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static void ethernet_reset(void)
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{
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unsigned int v;
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/* Reset the ethernet MAC. */
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v = __raw_readl(PHYS_ETH_SELF_CTL);
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__raw_writel(v | ETH_SELF_CTL_RESET, PHYS_ETH_SELF_CTL);
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/* Wait for reset to finish. */
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while (__raw_readl(PHYS_ETH_SELF_CTL) & ETH_SELF_CTL_RESET)
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;
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}
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static void arch_decomp_setup(void)
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{
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ethernet_reset();
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}
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