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>

diff --git a/drivers/platform/x86/samsung-laptop.c b/drivers/platform/x86/samsung-laptop.c
index 4787afdf11dc20e69af8fe5324366d4bd65aeb98..e2a34b42ddc1d584b5333fe9921d0d2c2b12dda4 100644 (file)
--- 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