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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: 60b7ab6ce0 ("platform: arm64: thinkpad-t14s-ec: new driver")
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Link: https://patch.msgid.link/20251119-thinkpad-t14s-ec-improvements-v2-2-441219857c02@kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
This commit is contained in:
Sebastian Reichel 2025-11-19 01:41:41 +01:00 committed by Ilpo Järvinen
parent 29be646f75
commit 752630cb8c
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1 changed files with 4 additions and 0 deletions
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4
drivers/platform/arm64/lenovo-thinkpad-t14s.c
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@ -120,6 +120,7 @@ static int t14s_ec_write(void *context, unsigned int reg,
if (ret < 0) if (ret < 0)
return ret; return ret;
fsleep(10000);
return 0; return 0;
} }
@ -157,6 +158,7 @@ static int t14s_ec_read(void *context, unsigned int reg,
out: out:
i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
fsleep(10000);
return ret; return ret;
} }
@ -191,6 +193,8 @@ static int t14s_ec_read_evt(struct t14s_ec *ec, u8 *val)
if (ret < 0) if (ret < 0)
goto out; goto out;
fsleep(10000);
ret = 0; ret = 0;
out: out: