Commit 87a84b69 authored by Shawn Guo's avatar Shawn Guo
Browse files

ARM: imx: replace imx6q_restart() with mxc_restart() 



The imx6q_restart() works fine with normal reboot but will run into
problem with emergency reboot like sysrq-b.  In that case, of_iomap()
gets called from interrupt context and hence triggers the BUG_ON in
__get_vm_area_node().

Actually, since commit c1e31d12 (ARM: imx: create
mxc_arch_reset_init_dt() for DT boot), imx6q/dl should try to use
mxc_restart() by calling mxc_arch_reset_init_dt() beforehand, where
things like of_iomap() can be done.

The patch updates mxc_restart() a little bit to get it work for imx6q/dl
and kill imx6q_restart() completely.

Reported-by: default avatarNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
parent 6fc6c93e

arch/arm/mach-imx/common.h

+4 −0
Original line number Diff line number Diff line
@@ -126,7 +126,11 @@ static inline void imx_smp_prepare(void) {} 
static inline void imx_scu_standby_enable(void) {}

#endif

extern void imx_src_init(void);

#ifdef CONFIG_HAVE_IMX_SRC

extern void imx_src_prepare_restart(void);

#else

static inline void imx_src_prepare_restart(void) {}

#endif

extern void imx_gpc_init(void);

extern void imx_gpc_pre_suspend(void);

extern void imx_gpc_post_resume(void);

arch/arm/mach-imx/mach-imx6q.c

+3 −32
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#include <linux/clk.h>

#include <linux/clkdev.h>

#include <linux/cpu.h>

#include <linux/delay.h>

#include <linux/export.h>

#include <linux/init.h>

#include <linux/io.h>
@@ -38,36 +37,6 @@ 
#include "cpuidle.h"

#include "hardware.h"



static void imx6q_restart(enum reboot_mode mode, const char *cmd)

{

	struct device_node *np;

	void __iomem *wdog_base;



	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-wdt");

	wdog_base = of_iomap(np, 0);

	if (!wdog_base)

		goto soft;



	imx_src_prepare_restart();



	/* enable wdog */

	writew_relaxed(1 << 2, wdog_base);

	/* write twice to ensure the request will not get ignored */

	writew_relaxed(1 << 2, wdog_base);



	/* wait for reset to assert ... */

	mdelay(500);



	pr_err("Watchdog reset failed to assert reset\n");



	/* delay to allow the serial port to show the message */

	mdelay(50);



soft:

	/* we'll take a jump through zero as a poor second */

	soft_restart(0);

}



/* For imx6q sabrelite board: set KSZ9021RN RGMII pad skew */

static int ksz9021rn_phy_fixup(struct phy_device *phydev)

{
@@ -167,6 +136,8 @@ static void __init imx6q_init_machine(void) 
	imx_print_silicon_rev(cpu_is_imx6dl() ? "i.MX6DL" : "i.MX6Q",

			      imx_get_soc_revision());



	mxc_arch_reset_init_dt();



	parent = imx_soc_device_init();

	if (parent == NULL)

		pr_warn("failed to initialize soc device\n");
@@ -285,5 +256,5 @@ DT_MACHINE_START(IMX6Q, "Freescale i.MX6 Quad/DualLite (Device Tree)") 
	.init_machine	= imx6q_init_machine,

	.init_late      = imx6q_init_late,

	.dt_compat	= imx6q_dt_compat,

	.restart	= imx6q_restart,

	.restart	= mxc_restart,

MACHINE_END

arch/arm/mach-imx/system.c

+5 −0
Original line number Diff line number Diff line
@@ -42,6 +42,9 @@ void mxc_restart(enum reboot_mode mode, const char *cmd) 
{

	unsigned int wcr_enable;



	if (cpu_is_imx6q() || cpu_is_imx6dl())

		imx_src_prepare_restart();



	if (wdog_clk)

		clk_enable(wdog_clk);
@@ -52,6 +55,8 @@ void mxc_restart(enum reboot_mode mode, const char *cmd) 


	/* Assert SRS signal */

	__raw_writew(wcr_enable, wdog_base);

	/* write twice to ensure the request will not get ignored */

	__raw_writew(wcr_enable, wdog_base);



	/* wait for reset to assert... */

	mdelay(500);

CRA Git | Maintained and supported by SUSTech CRA and CCSE