Mikko Rapeli wrote:
From: Mikko Rapeli <ext-mikko.rapeli@xxxxxxxxx>
Original patch: http://marc.info/?l=linux-omap&m=126522625032441&w=2
I forgot about this one...
"Removes TWL4030 sleep script prior to rebooting, only on OMAP3. This is
necessary since DPLL3 reset causes SYS_OFFMODE pin to go low, resulting
in the sleep script being executed on TWL4030. This usually results in
VDD1 & VDD2 voltage collapse while ROM code is executing, followed by an
MPU Watch Dog reset or worse, an irrecoverable hang."
Original patch resulted in a crash due to sleeping i2c calls late in the
reboot sequence. Here's how to trigger the crash:
# cat /dev/urandom > /foo &
sync();
reboot(LINUX_REBOOT_CMD_RESTART2);
Kernel trace from 2.6.32:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 805 [#2] PREEMPT
...
[<c00b3210>] (exit_mmap+0x1d4/0x1f8) from [<c006069c>] (mmput+0x34/0x110)
[<c006069c>] (mmput+0x34/0x110) from [<c0064a90>] (exit_mm+0x140/0x180)
[<c0064a90>] (exit_mm+0x140/0x180) from [<c00668ec>] (do_exit+0x5d8/0x6ac)
[<c00668ec>] (do_exit+0x5d8/0x6ac) from [<c0035858>] (die+0x2d4/0x2e0)
[<c0035858>] (die+0x2d4/0x2e0) from [<c0035904>] (baddataabort+0x0/0x50)
[<c0035904>] (baddataabort+0x0/0x50) from [<c0274ff4>] (i2c_transfer+0xec/0x104)
[<c0274ff4>] (i2c_transfer+0xec/0x104) from [<00000001>] (0x1)
Fix is to move reboot preparations into a reboot notifier.
Signed-off-by: Mikko Rapeli <ext-mikko.rapeli@xxxxxxxxx>
---
drivers/mfd/twl4030-power.c | 29 +++++++++++++++++++++++++++++
1 files changed, 29 insertions(+), 0 deletions(-)
diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
index 7efa878..5d46768 100644
--- a/drivers/mfd/twl4030-power.c
+++ b/drivers/mfd/twl4030-power.c
@@ -28,6 +28,7 @@
#include <linux/pm.h>
#include <linux/i2c/twl.h>
#include <linux/platform_device.h>
+#include <linux/reboot.h>
#include <asm/mach-types.h>
@@ -127,6 +128,29 @@ static u8 res_config_addrs[] = {
[RES_Main_Ref] = 0x94,
};
+/*
+ * PRCM on OMAP3 will drive SYS_OFFMODE low during DPLL3 warm reset.
+ * This causes Gaia sleep script to execute, usually killing VDD1 and
+ * VDD2 while code is running. WA is to disable the sleep script
+ * before warm reset.
+ */
+static int twl4030_prepare_for_reboot(struct notifier_block *this,
+ unsigned long cmd, void *p)
+{
+ int err;
+ err = twl4030_remove_script(TWL4030_SLEEP_SCRIPT);
+ if (err)
+ pr_err("TWL4030: error trying to disable sleep script!\n");
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block twl4030_reboot_notifier = {
+ .notifier_call = twl4030_prepare_for_reboot,
+ .next = NULL,
+ .priority = 0
+};
+
static int __init twl4030_write_script_byte(u8 address, u8 byte)
{
int err;
@@ -549,6 +573,11 @@ void __init twl4030_power_init(struct twl4030_power_data *twl4030_scripts)
err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0, R_PROTECT_KEY);
if (err)
pr_err("TWL4030 Unable to relock registers\n");
+
+ err = register_reboot_notifier(&twl4030_reboot_notifier);
This method is much better than the method I proposed before. Taking
into account the comments from others, ACK.
Mike
+ if (err)
+ pr_err("TWL4030 Failed to register reboot notifier\n");
+
return;
unlock:
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
