Kevin, It's true that this behavior is seen across all DM6467 EVMs. If this fix is not present then the terminal shows up error messages like "too much work for irq xx". After the EVM boots up, you can run the "tack" command to test this.
I am not in office today. I can work on the patch on Monday to change the hardcoded value of 0x8. Regards, Sudhakar ________________________________________ From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of Kevin Hilman [EMAIL PROTECTED] Sent: Friday, November 14, 2008 6:10 AM To: Steve Chen Cc: [email protected] Subject: Re: [PATCH v5 09/10] ARM: DaVinci: serial mis-behavior on dm646x Steve Chen <[EMAIL PROTECTED]> writes: > Kevin, > > I noticed the following code in your patch > + > + if (cpu_is_davinci_dm646x()) > + davinci_serial_outb(p, UART_DM646X_SCR, 0x8); > > You want to use writel. Less than 32bit Writes to the UART controller locks > up the ARM core. > Thanks for the check! With that info, I reworked the patch (see below) and just make all the serial writes at init time use 32-bit writes. Then there's a single reset function which works for all chips, with a special case for dm6467. Any objectsions? Kevin > > On Thursday 13 November 2008 16:15:36 Kevin Hilman wrote: >> Steve Chen <[EMAIL PROTECTED]> writes: >> >> > Kevin, >> > >> > On Thursday 13 November 2008 13:17:39 Kevin Hilman wrote: >> >> Is this misbehavior specific to the DM6467 EVM or common to any DM6467 >> >> board? The patch description could be a bit more descriptive in the >> >> future. >> > Last month, someone posted on the mailing list about UART2 not working his >> > custom board. As it turns out, he needed this same fix for UART2, so this >> > is >> > a generic dm6467 issue. >> >> OK, thanks for the clarification. That's what I was expecting. Then >> doing this in board init code is definitely wrong. >> >> > Also, this patch only fixes UART0. Do we want to consider something more >> > generic that addresses all three UARTs. >> >> Yes, I'd like to see something more generic. >> >> The 2nd patch I sent is an attempt at doing something more generic, >> but it doesn't boot. Since the initial mis-behavior was not well >> described in the initial patch, I'm hoping someone (like you :) might >> be able to shed some light on why my solution doesn't work. >> >> Kevin >> >From 45ab9e55aecb73472bd5f682cc68768df172bf11 Mon Sep 17 00:00:00 2001 From: Kevin Hilman <[EMAIL PROTECTED]> Date: Thu, 13 Nov 2008 11:10:04 -0800 Subject: [PATCH] DaVinci: DM646x: move serial reset from board code to chip code Signed-off-by: Kevin Hilman <[EMAIL PROTECTED]> --- arch/arm/mach-davinci/board-dm646x-evm.c | 14 ----------- arch/arm/mach-davinci/serial.c | 36 ++++++++++++++--------------- 2 files changed, 17 insertions(+), 33 deletions(-) diff --git a/arch/arm/mach-davinci/board-dm646x-evm.c b/arch/arm/mach-davinci/board-dm646x-evm.c index b6a2b22..f311f52 100644 --- a/arch/arm/mach-davinci/board-dm646x-evm.c +++ b/arch/arm/mach-davinci/board-dm646x-evm.c @@ -117,20 +117,6 @@ static void __init evm_init_i2c(void) i2c_register_board_info(1, i2c_info, ARRAY_SIZE(i2c_info)); } -#define UART_DM646X_SCR (DAVINCI_UART0_BASE + 0x40) -/* - * Internal UARTs need to be initialized for the 8250 autoconfig to work - * properly. Note that the TX watermark initialization may not be needed - * once the 8250.c watermark handling code is merged. - */ -static int __init dm646x_serial_reset(void) -{ - davinci_writel(0x08, UART_DM646X_SCR); - - return 0; -} -late_initcall(dm646x_serial_reset); - static void board_init(void) { davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DM646X_LPSC_AEMIF, 1); diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c index 1a08ef5..9198978 100644 --- a/arch/arm/mach-davinci/serial.c +++ b/arch/arm/mach-davinci/serial.c @@ -37,27 +37,22 @@ #include "clock.h" #define UART_DAVINCI_PWREMU 0x0c +#define UART_DM646X_SCR 0x10 + #define DM355_UART2_BASE (0x01E06000) -static inline unsigned int davinci_serial_in(struct plat_serial8250_port *up, - int offset) +static inline unsigned int serial_read_reg(struct plat_serial8250_port *up, + int offset) { offset <<= up->regshift; - return (unsigned int)__raw_readb(up->membase + offset); -} - -static inline void davinci_serial_outb(struct plat_serial8250_port *p, - int offset, int value) -{ - offset <<= p->regshift; - __raw_writeb(value, p->membase + offset); + return (unsigned int)__raw_readl(up->membase + offset); } -static inline void davinci_serial_outs(struct plat_serial8250_port *p, - int offset, int value) +static inline void serial_write_reg(struct plat_serial8250_port *p, int offset, + int value) { offset <<= p->regshift; - __raw_writew(value, p->membase + offset); + __raw_writel(value, p->membase + offset); } static struct plat_serial8250_port serial_platform_data[] = { @@ -103,17 +98,21 @@ static struct platform_device serial_device = { static void __init davinci_serial_reset(struct plat_serial8250_port *p) { - /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */ unsigned int pwremu = 0; - davinci_serial_outb(p, UART_IER, 0); /* disable all interrupts */ + serial_write_reg(p, UART_IER, 0); /* disable all interrupts */ - davinci_serial_outs(p, UART_DAVINCI_PWREMU, pwremu); + /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */ + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); mdelay(10); pwremu |= (0x3 << 13); pwremu |= 0x1; - davinci_serial_outs(p, UART_DAVINCI_PWREMU, pwremu); + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); + + if (cpu_is_davinci_dm646x()) { + serial_write_reg(p, UART_DM646X_SCR, 0x08); + } } void __init davinci_serial_init(void) @@ -166,8 +165,7 @@ void __init davinci_serial_init(void) __func__, __LINE__, i); else { clk_enable(uart_clk); - if (cpu_is_davinci_dm644x() || cpu_is_davinci_dm355()) - davinci_serial_reset(p); + davinci_serial_reset(p); } } } -- 1.6.0.3 _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source_______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
