It the device is probed in non-zero ACPI D state, the module identification is delayed until the first streamon.

The module identification has two parts: deviceID and version. To rea the version we have to enable OTP read. This cannot be done during streamon, becase it modifies REG_MODE_SELECT.

Since the driver has the same behaviour for all the module versions, do not read the module version from the sensor's OTP.

Cc: stable@vger.kernel.org Fixes: 0e014f1a8d54 ("media: ov8856: support device probe in non-zero ACPI D state") Signed-off-by: Ricardo Ribalda ribalda@chromium.org --- To: Dongchun Zhu dongchun.zhu@mediatek.com To: Mauro Carvalho Chehab mchehab@kernel.org To: Sakari Ailus sakari.ailus@linux.intel.com To: Bingbu Cao bingbu.cao@intel.com Cc: Max Staudt mstaudt@chromium.org Cc: Jimmy Su jimmy.su@intel.com Cc: Mauro Carvalho Chehab mchehab+huawei@kernel.org Cc: linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/media/i2c/ov8856.c | 40 ---------------------------------------- 1 file changed, 40 deletions(-)

diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c index cf8384e09413..b5c7881383ca 100644 --- a/drivers/media/i2c/ov8856.c +++ b/drivers/media/i2c/ov8856.c @@ -1709,46 +1709,6 @@ static int ov8856_identify_module(struct ov8856 *ov8856) return -ENXIO; }

- ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT, - OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING); - if (ret) - return ret; - - ret = ov8856_write_reg(ov8856, OV8856_OTP_MODE_CTRL, - OV8856_REG_VALUE_08BIT, OV8856_OTP_MODE_AUTO); - if (ret) { - dev_err(&client->dev, "failed to set otp mode"); - return ret; - } - - ret = ov8856_write_reg(ov8856, OV8856_OTP_LOAD_CTRL, - OV8856_REG_VALUE_08BIT, - OV8856_OTP_LOAD_CTRL_ENABLE); - if (ret) { - dev_err(&client->dev, "failed to enable load control"); - return ret; - } - - ret = ov8856_read_reg(ov8856, OV8856_MODULE_REVISION, - OV8856_REG_VALUE_08BIT, &val); - if (ret) { - dev_err(&client->dev, "failed to read module revision"); - return ret; - } - - dev_info(&client->dev, "OV8856 revision %x (%s) at address 0x%02x\n", - val, - val == OV8856_2A_MODULE ? "2A" : - val == OV8856_1B_MODULE ? "1B" : "unknown revision", - client->addr); - - ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT, - OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY); - if (ret) { - dev_err(&client->dev, "failed to exit streaming mode"); - return ret; - } - ov8856->identified = true;

return 0;

--- base-commit: 9fd6ba5420ba2b637d1ecc6de8613ec8b9c87e5a change-id: 20230323-ov8856-otp-112f3cdc74b1

Best regards,