From f8b7d5ba99ab0812c900d59c2d7b102fb4e8b0fa Mon Sep 17 00:00:00 2001 From: Zixing Liu Date: Fri, 24 Jul 2026 16:33:14 +0800 Subject: [PATCH] platform/loongarch: laptop: Explicitly reset bl_powered state when suspend commit 91a70492c03040d51b36f595530d6491d5d6c541 upstream. On EAECIS NL60R with EC firmware version 1.11, resuming from S3 has a very high chance (>90%) of causing the EC to lose the previous backlight power state. When this happens, the laptop resumes normally from S3, but the backlight remains off (when shining on the screen with a flash light, we can see the screen contents are updating normally). Since there is no generic way to query the EC's backlight state on Loongson laptop platforms, assume the worst-case scenario and restart the backlight power inside the kernel each time the system resumes. Cc: stable@vger.kernel.org Fixes: 53c762b47f72 ("platform/loongarch: laptop: Add backlight power control support") Tested-by: Yao Zi Tested-by: Xi Ruoyao Signed-off-by: Zixing Liu Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman --- drivers/platform/loongarch/loongson-laptop.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c index 5fcfa3a7970b..f3adee7515d3 100644 --- a/drivers/platform/loongarch/loongson-laptop.c +++ b/drivers/platform/loongarch/loongson-laptop.c @@ -189,6 +189,7 @@ static int __init setup_acpi_notify(struct generic_sub_driver *sub_driver) static int loongson_hotkey_suspend(struct device *dev) { + bl_powered = false; return 0; }