Input: i8042 - skip selftest on ASUS laptops

On suspend/resume cycle, selftest is executed to reset i8042 controller.
But when this is done in Asus devices, subsequent 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 as a
kernel parameter. On Asus laptops, it'll make the system to start with the
touchpad already stuck, since psmouse_probe forcibly calls the selftest
function.

This patch was inspired by John Hiesey's change[1], but, since this problem
affects a lot of models of Asus, let's avoid running selftests on them.

All models affected by this problem:
A455LD
K401LB
K501LB
K501LX
R409L
V502LX
X302LA
X450LCP
X450LD
X455LAB
X455LDB
X455LF
Z450LA

[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>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

7 files changed, 142 insertions, 19 deletions

diff --git a/drivers/input/serio/i8042-io.h b/drivers/input/serio/i8042-io.h
index a5eed2ade53d..34da81c006b6 100644
--- a/drivers/input/serio/i8042-io.h
+++ b/drivers/input/serio/i8042-io.h
@@ -81,7 +81,7 @@ static inline int i8042_platform_init(void)
                 return -EBUSY;
 #endif
 
-        i8042_reset = 1;
+        i8042_reset = I8042_RESET_ALWAYS;
         return 0;
 }
 
diff --git a/drivers/input/serio/i8042-ip22io.h b/drivers/input/serio/i8042-ip22io.h
index ee1ad27d6ed0..08a1c10a1448 100644
--- a/drivers/input/serio/i8042-ip22io.h
+++ b/drivers/input/serio/i8042-ip22io.h
@@ -61,7 +61,7 @@ static inline int i8042_platform_init(void)
                 return -EBUSY;
 #endif
 
-        i8042_reset = 1;
+        i8042_reset = I8042_RESET_ALWAYS;
 
         return 0;
 }
diff --git a/drivers/input/serio/i8042-ppcio.h b/drivers/input/serio/i8042-ppcio.h
index f708c75d16f1..1aabea43329e 100644
--- a/drivers/input/serio/i8042-ppcio.h
+++ b/drivers/input/serio/i8042-ppcio.h
@@ -44,7 +44,7 @@ static inline void i8042_write_command(int val)
 
 static inline int i8042_platform_init(void)
 {
-        i8042_reset = 1;
+        i8042_reset = I8042_RESET_ALWAYS;
         return 0;
 }
 
diff --git a/drivers/input/serio/i8042-sparcio.h b/drivers/input/serio/i8042-sparcio.h
index afcd1c1a05b2..6231d63860ee 100644
--- a/drivers/input/serio/i8042-sparcio.h
+++ b/drivers/input/serio/i8042-sparcio.h
@@ -130,7 +130,7 @@ static int __init i8042_platform_init(void)
                 }
         }
 
-        i8042_reset = 1;
+        i8042_reset = I8042_RESET_ALWAYS;
 
         return 0;
 }
diff --git a/drivers/input/serio/i8042-unicore32io.h b/drivers/input/serio/i8042-unicore32io.h
index 73f5cc124a36..455747552f85 100644
--- a/drivers/input/serio/i8042-unicore32io.h
+++ b/drivers/input/serio/i8042-unicore32io.h
@@ -61,7 +61,7 @@ static inline int i8042_platform_init(void)
         if (!request_mem_region(I8042_REGION_START, I8042_REGION_SIZE, "i8042"))
                 return -EBUSY;
 
-        i8042_reset = 1;
+        i8042_reset = I8042_RESET_ALWAYS;
         return 0;
 }
 
diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index 68f5f4a0f1e7..f4bfb4b2d50a 100644
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -510,6 +510,90 @@ static const struct dmi_system_id __initconst i8042_dmi_nomux_table[] = {
         { }
 };
 
+/*
+ * On some Asus laptops, just running self tests cause problems.
+ */
+static const struct dmi_system_id i8042_dmi_noselftest_table[] = {
+        {
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "A455LD"),
+                },
+        },
+        {
+                .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, "K501LX"),
+                },
+        },
+        {
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "R409L"),
+                },
+        },
+        {
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "V502LX"),
+                },
+        },
+        {
+                .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"),
+                },
+        },
+        {
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "X455LF"),
+                },
+        },
+        {
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "Z450LA"),
+                },
+        },
+        { }
+};
 static const struct dmi_system_id __initconst i8042_dmi_reset_table[] = {
         {
                 /* MSI Wind U-100 */
@@ -1072,12 +1156,18 @@ static int __init i8042_platform_init(void)
                 return retval;
 
 #if defined(__ia64__)
-        i8042_reset = true;
+        i8042_reset = I8042_RESET_ALWAYS;
 #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_DEFAULT) {
+                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 b4d34086e73f..674a760f5221 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -48,9 +48,39 @@ 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_S2RAM,
+#define I8042_RESET_DEFAULT     I8042_RESET_ON_S2RAM
+};
+static enum i8042_controller_reset_mode i8042_reset = I8042_RESET_DEFAULT;
+static int i8042_set_reset(const char *val, const struct kernel_param *kp)
+{
+        enum i8042_controller_reset_mode *arg = kp->arg;
+        int error;
+        bool reset;
+
+        if (val) {
+                error = kstrtobool(val, &reset);
+                if (error)
+                        return error;
+        } else {
+                reset = true;
+        }
+
+        *arg = reset ? I8042_RESET_ALWAYS : I8042_RESET_NEVER;
+        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, enum i8042_controller_reset_mode)
+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);
@@ -1019,7 +1049,7 @@ static int i8042_controller_init(void)
  * Reset the controller and reset CRT to the original value set by BIOS.
  */
 
-static void i8042_controller_reset(bool force_reset)
+static void i8042_controller_reset(bool s2r_wants_reset)
 {
         i8042_flush();
 
@@ -1044,8 +1074,10 @@ static void i8042_controller_reset(bool force_reset)
  * Reset the controller if requested.
  */
 
-        if (i8042_reset || force_reset)
+        if (i8042_reset == I8042_RESET_ALWAYS ||
+            (i8042_reset == I8042_RESET_ON_S2RAM && s2r_wants_reset)) {
                 i8042_controller_selftest();
+        }
 
 /*
  * Restore the original control register setting.
@@ -1110,7 +1142,7 @@ static void i8042_dritek_enable(void)
  * before suspending.
  */
 
-static int i8042_controller_resume(bool force_reset)
+static int i8042_controller_resume(bool s2r_wants_reset)
 {
         int error;
 
@@ -1118,7 +1150,8 @@ static int i8042_controller_resume(bool force_reset)
         if (error)
                 return error;
 
-        if (i8042_reset || force_reset) {
+        if (i8042_reset == I8042_RESET_ALWAYS ||
+            (i8042_reset == I8042_RESET_ON_S2RAM && s2r_wants_reset)) {
                 error = i8042_controller_selftest();
                 if (error)
                         return error;
@@ -1195,7 +1228,7 @@ static int i8042_pm_resume_noirq(struct device *dev)
 
 static int i8042_pm_resume(struct device *dev)
 {
-        bool force_reset;
+        bool want_reset;
         int i;
 
         for (i = 0; i < I8042_NUM_PORTS; i++) {
@@ -1218,9 +1251,9 @@ static int i8042_pm_resume(struct device *dev)
          * off control to the platform firmware, otherwise we can simply restore
          * the mode.
          */
-        force_reset = pm_resume_via_firmware();
+        want_reset = pm_resume_via_firmware();
 
-        return i8042_controller_resume(force_reset);
+        return i8042_controller_resume(want_reset);
 }
 
 static int i8042_pm_thaw(struct device *dev)
@@ -1481,7 +1514,7 @@ 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;