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authorTakashi Iwai <tiwai@suse.de>2017-01-11 19:49:27 +0100
committerTakashi Iwai <tiwai@suse.de>2017-01-11 19:49:27 +0100
commit6cf4569ce3561dec560147e6051959d6896b23d1 (patch)
tree2b3dca47673824975c35a708a6d9d24ff46a2771 /drivers/acpi/sysfs.c
parent2e40795c3bf344cfb5220d94566205796e3ef19a (diff)
parent42e0ebdef53d91891939a475c6ef23970829ff99 (diff)
Merge tag 'asoc-fix-v4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v4.10 As well as the usual smattering of driver specific fixes collected since the merge window this has one particularly important fix to the core for handling of aux_devs which was broken during the merge window by some of the componentization refactoring.
Diffstat (limited to 'drivers/acpi/sysfs.c')
-rw-r--r--drivers/acpi/sysfs.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 703c26e7022c..cf05ae973381 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -708,6 +708,62 @@ end:
return result ? result : size;
}
+/*
+ * A Quirk Mechanism for GPE Flooding Prevention:
+ *
+ * Quirks may be needed to prevent GPE flooding on a specific GPE. The
+ * flooding typically cannot be detected and automatically prevented by
+ * ACPI_GPE_DISPATCH_NONE check because there is a _Lxx/_Exx prepared in
+ * the AML tables. This normally indicates a feature gap in Linux, thus
+ * instead of providing endless quirk tables, we provide a boot parameter
+ * for those who want this quirk. For example, if the users want to prevent
+ * the GPE flooding for GPE 00, they need to specify the following boot
+ * parameter:
+ * acpi_mask_gpe=0x00
+ * The masking status can be modified by the following runtime controlling
+ * interface:
+ * echo unmask > /sys/firmware/acpi/interrupts/gpe00
+ */
+
+/*
+ * Currently, the GPE flooding prevention only supports to mask the GPEs
+ * numbered from 00 to 7f.
+ */
+#define ACPI_MASKABLE_GPE_MAX 0x80
+
+static u64 __initdata acpi_masked_gpes;
+
+static int __init acpi_gpe_set_masked_gpes(char *val)
+{
+ u8 gpe;
+
+ if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
+ return -EINVAL;
+ acpi_masked_gpes |= ((u64)1<<gpe);
+
+ return 1;
+}
+__setup("acpi_mask_gpe=", acpi_gpe_set_masked_gpes);
+
+void __init acpi_gpe_apply_masked_gpes(void)
+{
+ acpi_handle handle;
+ acpi_status status;
+ u8 gpe;
+
+ for (gpe = 0;
+ gpe < min_t(u8, ACPI_MASKABLE_GPE_MAX, acpi_current_gpe_count);
+ gpe++) {
+ if (acpi_masked_gpes & ((u64)1<<gpe)) {
+ status = acpi_get_gpe_device(gpe, &handle);
+ if (ACPI_SUCCESS(status)) {
+ pr_info("Masking GPE 0x%x.\n", gpe);
+ (void)acpi_mask_gpe(handle, gpe, TRUE);
+ }
+ }
+ }
+}
+
void acpi_irq_stats_init(void)
{
acpi_status status;