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path: root/drivers/platform/x86/ideapad-laptop.c
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Diffstat (limited to 'drivers/platform/x86/ideapad-laptop.c')
-rw-r--r--drivers/platform/x86/ideapad-laptop.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index ede483573fe0..b5e4da6a6779 100644
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -15,6 +15,7 @@
#include <linux/bug.h>
#include <linux/cleanup.h>
#include <linux/debugfs.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/i8042.h>
@@ -267,6 +268,20 @@ static void ideapad_shared_exit(struct ideapad_private *priv)
*/
#define IDEAPAD_EC_TIMEOUT 200 /* in ms */
+/*
+ * Some models (e.g., ThinkBook since 2024) have a low tolerance for being
+ * polled too frequently. Doing so may break the state machine in the EC,
+ * resulting in a hard shutdown.
+ *
+ * It is also observed that frequent polls may disturb the ongoing operation
+ * and notably delay the availability of EC response.
+ *
+ * These values are used as the delay before the first poll and the interval
+ * between subsequent polls to solve the above issues.
+ */
+#define IDEAPAD_EC_POLL_MIN_US 150
+#define IDEAPAD_EC_POLL_MAX_US 300
+
static int eval_int(acpi_handle handle, const char *name, unsigned long *res)
{
unsigned long long result;
@@ -383,7 +398,7 @@ static int read_ec_data(acpi_handle handle, unsigned long cmd, unsigned long *da
end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1;
while (time_before(jiffies, end_jiffies)) {
- schedule();
+ usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US);
err = eval_vpcr(handle, 1, &val);
if (err)
@@ -414,7 +429,7 @@ static int write_ec_cmd(acpi_handle handle, unsigned long cmd, unsigned long dat
end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1;
while (time_before(jiffies, end_jiffies)) {
- schedule();
+ usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US);
err = eval_vpcr(handle, 1, &val);
if (err)