samsung-laptop: unregister ACPI video module for some well known laptops

On these laptops, the ACPI video is not functional, and very unlikely
to be fixed by the vendor. Note that intel_backlight works for some
of these laptops, and the backlight from samsung-laptop always work.

The good news is that newer laptops have functional ACPI video device
and won't end up growing this list.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 76 insertions, 4 deletions

diff --git a/drivers/platform/x86/samsung-laptop.c b/drivers/platform/x86/samsung-laptop.c
index 4787afdf11d..e2a34b42ddc 100644
--- a/drivers/platform/x86/samsung-laptop.c
+++ b/drivers/platform/x86/samsung-laptop.c
@@ -26,6 +26,9 @@
 #include <linux/seq_file.h>
 #include <linux/debugfs.h>
 #include <linux/ctype.h>
+#if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
+#include <acpi/video.h>
+#endif
 
 /*
  * This driver is needed because a number of Samsung laptops do not hook
@@ -336,6 +339,7 @@ struct samsung_laptop {
         struct work_struct kbd_led_work;
 
         struct samsung_laptop_debug debug;
+        struct samsung_quirks *quirks;
 
         bool handle_backlight;
         bool has_stepping_quirk;
@@ -343,7 +347,15 @@ struct samsung_laptop {
         char sdiag[64];
 };
 
+struct samsung_quirks {
+        bool broken_acpi_video;
+};
+
+static struct samsung_quirks samsung_unknown = {};
 
+static struct samsung_quirks samsung_broken_acpi_video = {
+        .broken_acpi_video = true,
+};
 
 static bool force;
 module_param(force, bool, 0);
@@ -1416,6 +1428,14 @@ static int __init samsung_platform_init(struct samsung_laptop *samsung)
         return 0;
 }
 
+static struct samsung_quirks *quirks;
+
+static int __init samsung_dmi_matched(const struct dmi_system_id *d)
+{
+        quirks = d->driver_data;
+        return 0;
+}
+
 static struct dmi_system_id __initdata samsung_dmi_table[] = {
         {
                 .matches = {
@@ -1445,6 +1465,47 @@ static struct dmi_system_id __initdata samsung_dmi_table[] = {
                         DMI_MATCH(DMI_CHASSIS_TYPE, "14"), /* Sub-Notebook */
                 },
         },
+        /* Specific DMI ids for laptop with quirks */
+        {
+         .callback = samsung_dmi_matched,
+         .ident = "N150P",
+         .matches = {
+                DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+                DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
+                DMI_MATCH(DMI_BOARD_NAME, "N150P"),
+                },
+         .driver_data = &samsung_broken_acpi_video,
+        },
+        {
+         .callback = samsung_dmi_matched,
+         .ident = "N145P/N250P/N260P",
+         .matches = {
+                DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+                DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
+                DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
+                },
+         .driver_data = &samsung_broken_acpi_video,
+        },
+        {
+         .callback = samsung_dmi_matched,
+         .ident = "N150/N210/N220",
+         .matches = {
+                DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+                DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
+                DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
+                },
+         .driver_data = &samsung_broken_acpi_video,
+        },
+        {
+         .callback = samsung_dmi_matched,
+         .ident = "NF110/NF210/NF310",
+         .matches = {
+                DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+                DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
+                DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
+                },
+         .driver_data = &samsung_broken_acpi_video,
+        },
         { },
 };
 MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
@@ -1456,6 +1517,7 @@ static int __init samsung_init(void)
         struct samsung_laptop *samsung;
         int ret;
 
+        quirks = &samsung_unknown;
         if (!force && !dmi_check_system(samsung_dmi_table))
                 return -ENODEV;
 
@@ -1465,12 +1527,21 @@ static int __init samsung_init(void)
 
         mutex_init(&samsung->sabi_mutex);
         samsung->handle_backlight = true;
+        samsung->quirks = quirks;
 
-#ifdef CONFIG_ACPI
+
+#if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
         /* Don't handle backlight here if the acpi video already handle it */
-        if (acpi_video_backlight_support())
-                samsung->handle_backlight = false;
+        if (acpi_video_backlight_support()) {
+                if (samsung->quirks->broken_acpi_video) {
+                        pr_info("Disabling ACPI video driver\n");
+                        acpi_video_unregister();
+                } else {
+                        samsung->handle_backlight = false;
+                }
+        }
 #endif
+
         ret = samsung_platform_init(samsung);
         if (ret)
                 goto error_platform;
@@ -1481,7 +1552,8 @@ static int __init samsung_init(void)
 
 #ifdef CONFIG_ACPI
         /* Only log that if we are really on a sabi platform */
-        if (acpi_video_backlight_support())
+        if (acpi_video_backlight_support() &&
+            !samsung->quirks->broken_acpi_video)
                 pr_info("Backlight controlled by ACPI video driver\n");
 #endif