[PATCH v2 0/2] Skip i8042 selftest on some ASUS laptops

[PATCH v2 0/2] Skip i8042 selftest on some ASUS laptops

[Marcos Paulo de Souza]

Hi guys,

second version of the patch, addressing comments of Dmitry.

Changes since v1: 
Use reset parameter, instead of adding reset_mode parameter.
Change reset parameter from bool to unsigned int.

Marcos Paulo de Souza (2):
  input/serio/i8042.c: Skipt selftest on some ASUS laptops
  kernel-parameters: Update i8042.reset parameter documentation

 Documentation/kernel-parameters.txt   |  7 +++-
 drivers/input/serio/i8042-x86ia64io.h | 70 ++++++++++++++++++++++++++++++++++-
 drivers/input/serio/i8042.c           | 38 ++++++++++++++++---
 3 files changed, 106 insertions(+), 9 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] input/serio/i8042.c: Skipt selftest on some ASUS laptops

[Marcos Paulo de Souza]

On suspend/resume cycle, selftest is executed on to reset i8042 controller. But
when this is done in these devices, posterior calls to detect/init functions
to elantech driver fails. Skipping selftest fixes this problem.

An easier step to reproduce this problem is adding i8042.reset=1 parameter.
On problematic laptops, it'll make the system to start with the
touchpad already stucked, since i8042 code forcibly calls the selftest function.

This patch was inspired by John Hiesey's change[1].

[1]: https://marc.info/?l=linux-input&m=144312209020616&w=2

Fixes: "ETPS/2 Elantech Touchpad dies after resume from suspend" (https://bugzilla.kernel.org/show_bug.cgi?id=107971)

Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
---
 drivers/input/serio/i8042-x86ia64io.h | 70 ++++++++++++++++++++++++++++++++++-
 drivers/input/serio/i8042.c           | 38 ++++++++++++++++---
 2 files changed, 100 insertions(+), 8 deletions(-)

diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index 68f5f4a..0107976 100644
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -510,6 +510,66 @@ static const struct dmi_system_id __initconst i8042_dmi_nomux_table[] = {
 	{ }
 };
 
+/*
+ * On some hardware just running the self test causes problems.
+ */
+static const struct dmi_system_id __initconst i8042_dmi_noselftest_table[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "K401LB"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "K501LB"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "K501LD"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "K501LX"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X302LA"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X450LCP"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X450LD"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X455LAB"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X455LDB"),
+		},
+	},
+	{ }
+};
 static const struct dmi_system_id __initconst i8042_dmi_reset_table[] = {
 	{
 		/* MSI Wind U-100 */
@@ -1076,8 +1136,14 @@ static int __init i8042_platform_init(void)
 #endif
 
 #ifdef CONFIG_X86
-	if (dmi_check_system(i8042_dmi_reset_table))
-		i8042_reset = true;
+	/* Honor module parameter when value is not default */
+	if (i8042_reset == I8042_RESET_ON_RESUME) {
+		if (dmi_check_system(i8042_dmi_reset_table))
+			i8042_reset = I8042_RESET_ALWAYS;
+
+		if (dmi_check_system(i8042_dmi_noselftest_table))
+			i8042_reset = I8042_RESET_NEVER;
+	}
 
 	if (dmi_check_system(i8042_dmi_noloop_table))
 		i8042_noloop = true;
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 4541957..28ce5d2 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -48,9 +48,32 @@ static bool i8042_unlock;
 module_param_named(unlock, i8042_unlock, bool, 0);
 MODULE_PARM_DESC(unlock, "Ignore keyboard lock.");
 
-static bool i8042_reset;
-module_param_named(reset, i8042_reset, bool, 0);
-MODULE_PARM_DESC(reset, "Reset controller during init and cleanup.");
+enum i8042_controller_reset_mode {
+	I8042_RESET_NEVER,
+	I8042_RESET_ALWAYS,
+	I8042_RESET_ON_RESUME
+};
+static unsigned int i8042_reset = I8042_RESET_ON_RESUME;
+static int i8042_set_reset(const char *val, const struct kernel_param *kp)
+{
+	unsigned int ret = I8042_RESET_ON_RESUME;
+        if (!val || !strncmp(val, "1", 1) || !strncasecmp(val, "y", 1))
+		ret = I8042_RESET_ALWAYS;
+	else if (!strncmp(val, "0", 1) || !strncasecmp(val, "n", 1))
+		ret = I8042_RESET_NEVER;
+
+        *((unsigned int *)kp->arg) = ret;
+
+        return 0;
+}
+
+static const struct kernel_param_ops param_ops_reset_param = {
+	.flags = KERNEL_PARAM_OPS_FL_NOARG,
+	.set = i8042_set_reset,
+};
+#define param_check_reset_param(name, p) __param_check(name, p, unsigned int)
+module_param_named(reset, i8042_reset, reset_param, 0);
+MODULE_PARM_DESC(reset, "Reset controller on resume, cleanup or both");
 
 static bool i8042_direct;
 module_param_named(direct, i8042_direct, bool, 0);
@@ -890,6 +913,9 @@ static int i8042_controller_selftest(void)
 	unsigned char param;
 	int i = 0;
 
+	if (i8042_reset == I8042_RESET_NEVER)
+		return 0;
+
 	/*
 	 * We try this 5 times; on some really fragile systems this does not
 	 * take the first time...
@@ -1044,7 +1070,7 @@ static void i8042_controller_reset(bool force_reset)
  * Reset the controller if requested.
  */
 
-	if (i8042_reset || force_reset)
+	if (force_reset)
 		i8042_controller_selftest();
 
 /*
@@ -1118,7 +1144,7 @@ static int i8042_controller_resume(bool force_reset)
 	if (error)
 		return error;
 
-	if (i8042_reset || force_reset) {
+	if (force_reset) {
 		error = i8042_controller_selftest();
 		if (error)
 			return error;
@@ -1495,7 +1521,7 @@ static int __init i8042_probe(struct platform_device *dev)
 
 	i8042_platform_device = dev;
 
-	if (i8042_reset) {
+	if (i8042_reset == I8042_RESET_ALWAYS) {
 		error = i8042_controller_selftest();
 		if (error)
 			return error;
-- 
2.7.4

[PATCH v2 2/2] kernel-parameters: Update i8042.reset parameter documentation

[Marcos Paulo de Souza]

Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
---
 Documentation/kernel-parameters.txt | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 82b42c9..24dd5cc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1430,7 +1430,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	i8042.nopnp	[HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
 			     controllers
 	i8042.notimeout	[HW] Ignore timeout condition signalled by controller
-	i8042.reset	[HW] Reset the controller during init and cleanup
+	i8042.reset	[HW] Reset the controller during init and cleanup, only
+			     on cleanup, or never reset
+			Format: { 1 | Y | y | 0 | N | n }
+			1, Y, y: init and cleanup
+			0, N, n: don't reset controller
+			Default: only on cleanup
 	i8042.unlock	[HW] Unlock (ignore) the keylock
 	i8042.kbdreset  [HW] Reset device connected to KBD port
 
-- 
2.7.4