On 10/17/24 20:09, James Hilliard wrote:
For the watchdog timer to work properly on the QCML04 board we need to
set PWRGD enable in the Environment Controller Configuration Registers
Special Configuration Register 1 when it is not already set, this may
be the case when the watchdog is not enabled from within the BIOS.
For the Qotom QGLK02 board the vendor indicates that the IT8786
watchdog hardware is not functional due to a conflict with the BIOS
power-on function, with PWRGD set the watchdog will trigger but the
board will poweroff rather than restart as expected. Disable the
it87 driver on this broken hardware.
This shouldn't be done in drivers, and it doesn't scale. The driver needs
to be disabled with the mechanism supported by the distribution, for example
in /etc/modprobe.d/blacklist-watchdog.conf, or by whatever other mechanism
the distribution supports for that purpose.
Guenter
Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
---
drivers/watchdog/it87_wdt.c | 55 +++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/drivers/watchdog/it87_wdt.c b/drivers/watchdog/it87_wdt.c
index 3e8c15138edd..dec501c21fd3 100644
--- a/drivers/watchdog/it87_wdt.c
+++ b/drivers/watchdog/it87_wdt.c
@@ -20,6 +20,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -40,6 +41,7 @@
#define VAL 0x2f
/* Logical device Numbers LDN */
+#define EC 0x04
#define GPIO 0x07
/* Configuration Registers and Functions */
@@ -73,6 +75,12 @@
#define IT8784_ID 0x8784
#define IT8786_ID 0x8786
+/* Environment Controller Configuration Registers LDN=0x04 */
+#define SCR1 0xfa
+
+/* Environment Controller Bits SCR1 */
+#define WDT_PWRGD 0x20
+
/* GPIO Configuration Registers LDN=0x07 */
#define WDTCTRL 0x71
#define WDTCFG 0x72
@@ -240,6 +248,28 @@ static int wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
return ret;
}
+enum {
+ IT87_WDT_BROKEN = BIT(0),
+ IT87_WDT_OUTPUT_THROUGH_PWRGD = BIT(1),
+};
+
+static const struct dmi_system_id it8786_quirks[] = {
+ {
+ /* Qotom Q730P/Q8XXG2-P */
+ .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "QGLK02"),
+ },
+ .driver_data = (void *)IT87_WDT_BROKEN,
+ },
+ {
+ /* Qotom Q30900P */
+ .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "QCML04"),
+ },
+ .driver_data = (void *)IT87_WDT_OUTPUT_THROUGH_PWRGD,
+ }
+};
+
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.firmware_version = 1,
@@ -261,8 +291,10 @@ static struct watchdog_device wdt_dev = {
static int __init it87_wdt_init(void)
{
+ const struct dmi_system_id *dmi_id;
u8 chip_rev;
u8 ctrl;
+ int quirks = 0;
int rc;
rc = superio_enter();
@@ -273,6 +305,20 @@ static int __init it87_wdt_init(void)
chip_rev = superio_inb(CHIPREV) & 0x0f;
superio_exit();
+ switch (chip_type) {
+ case IT8786_ID:
+ dmi_id = dmi_first_match(it8786_quirks);
+ break;
+ default:
+ dmi_id = NULL;
+ }
+
+ if (dmi_id)
+ quirks = (long)dmi_id->driver_data;
+
+ if (quirks & IT87_WDT_BROKEN)
+ return -ENODEV;
+
switch (chip_type) {
case IT8702_ID:
max_units = 255;
@@ -333,6 +379,15 @@ static int __init it87_wdt_init(void)
superio_outb(0x00, WDTCTRL);
}
+ if (quirks & IT87_WDT_OUTPUT_THROUGH_PWRGD) {
+ superio_select(EC);
+ ctrl = superio_inb(SCR1);
+ if (!(ctrl & WDT_PWRGD)) {
+ ctrl |= WDT_PWRGD;
+ superio_outb(ctrl, SCR1);
+ }
+ }
+
superio_exit();
if (timeout < 1 || timeout > max_units * 60) {
