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authorHans de Goede <hdegoede@redhat.com>2018-08-12 12:53:20 +0200
committerWolfram Sang <wsa@the-dreams.de>2018-08-20 14:08:59 +0200
commitc463a158cb6c5d9a85b7d894cd4f8116e8bd6be0 (patch)
tree79409b9768a4d61566854458924ede06441b4198 /drivers/i2c/i2c-core-acpi.c
parent0857f50807709ae109b9d11d7ca88c44dc7ca99f (diff)
i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes
acpi_gsb_i2c_write_bytes() returns i2c_transfer()'s return value, which is the number of transfers executed on success, so 1. The ACPI code expects us to store 0 in gsb->status for success, not 1. Specifically this breaks the following code in the Thinkpad 8 DSDT: ECWR = I2CW = ECWR /* \_SB_.I2C1.BAT0.ECWR */ If ((ECST == Zero)) { ECRD = I2CR /* \_SB_.I2C1.I2CR */ } Before this commit we set ECST to 1, causing the read to never happen breaking battery monitoring on the Thinkpad 8. This commit makes acpi_gsb_i2c_write_bytes() return 0 when i2c_transfer() returns 1, so the single write transfer completed successfully, and makes it return -EIO on for other (unexpected) return values >= 0. Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/i2c-core-acpi.c')
-rw-r--r--drivers/i2c/i2c-core-acpi.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 7c3b4740b94b..b8f303dea305 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -482,11 +482,16 @@ static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
msgs[0].buf = buffer;
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
- if (ret < 0)
- dev_err(&client->adapter->dev, "i2c write failed\n");
kfree(buffer);
- return ret;
+
+ if (ret < 0) {
+ dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
+ return ret;
+ }
+
+ /* 1 transfer must have completed successfully */
+ return (ret == 1) ? 0 : -EIO;
}
static acpi_status