From: Sebastian Reichel Date: Wed, 19 Nov 2025 00:41:41 +0000 (+0100) Subject: platform: arm64: thinkpad-t14s-ec: sleep after EC access X-Git-Tag: v6.18~20^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=752630cb8c62abca0407f96cc7baa2e13335cd15;p=thirdparty%2Flinux.git platform: arm64: thinkpad-t14s-ec: sleep after EC access The ACPI ECRD and ECWR functions have a 10ms sleep at the end. It turns out, that this is sometimes needed to avoid I2C transmission failures, especially for functions doing regmap_update_bits (and thus read + write shortly after each other). This fixes problems like the following appearing in the kernel log: leds platform::micmute: Setting an LED's brightness failed (-6) leds platform::kbd_backlight: Setting an LED's brightness failed (-6) The ACPI QEVT function used to read the interrupt status register also has a 10ms sleep at the end. Without that there are problems with reading multiple events following directly after each other resulting in the following error message being logged: thinkpad-t14s-ec 4-0028: Failed to read event Fixes: 60b7ab6ce030 ("platform: arm64: thinkpad-t14s-ec: new driver") Signed-off-by: Sebastian Reichel Link: https://patch.msgid.link/20251119-thinkpad-t14s-ec-improvements-v2-2-441219857c02@kernel.org Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- diff --git a/drivers/platform/arm64/lenovo-thinkpad-t14s.c b/drivers/platform/arm64/lenovo-thinkpad-t14s.c index c1c01b977f2b..cf6a1d3b2617 100644 --- a/drivers/platform/arm64/lenovo-thinkpad-t14s.c +++ b/drivers/platform/arm64/lenovo-thinkpad-t14s.c @@ -120,6 +120,7 @@ static int t14s_ec_write(void *context, unsigned int reg, if (ret < 0) return ret; + fsleep(10000); return 0; } @@ -157,6 +158,7 @@ static int t14s_ec_read(void *context, unsigned int reg, out: i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); + fsleep(10000); return ret; } @@ -191,6 +193,8 @@ static int t14s_ec_read_evt(struct t14s_ec *ec, u8 *val) if (ret < 0) goto out; + fsleep(10000); + ret = 0; out: