| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 15 Dec 2021 11:13:03 +0800
From: Bingbu Cao <bingbu.cao@...ux.intel.com>
To: Sakari Ailus <sakari.ailus@...ux.intel.com>,
Bingbu Cao <bingbu.cao@...el.com>
Cc: linux-media@...r.kernel.org, rafael@...nel.org,
shawnx.tu@...el.com, tian.shu.qiu@...el.com,
chiranjeevi.rapolu@...el.com, hyungwoo.yang@...el.com,
tfiga@...omium.org, senozhatsky@...omium.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/6] media: imx208: Support device probe in non-zero ACPI
D state
On 12/14/21 11:59 PM, Sakari Ailus wrote:
> Hi Bingbu,
>
> On Tue, Nov 09, 2021 at 04:48:33PM +0800, Bingbu Cao wrote:
>> Tell ACPI device PM code that the driver supports the device being in
>> non-zero ACPI D state when the driver's probe function is entered.
>>
>> Also do identification on the first access of the device, whether in probe
>> or when starting streaming.
>>
>> Signed-off-by: Bingbu Cao <bingbu.cao@...el.com>
>> ---
>> drivers/media/i2c/imx208.c | 77 +++++++++++++++++++++++++++++-----------------
>> 1 file changed, 48 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/media/i2c/imx208.c b/drivers/media/i2c/imx208.c
>> index 6f3d9c1b5879..b9f6d5f33b58 100644
>> --- a/drivers/media/i2c/imx208.c
>> +++ b/drivers/media/i2c/imx208.c
>> @@ -296,6 +296,9 @@ struct imx208 {
>> /* OTP data */
>> bool otp_read;
>> char otp_data[IMX208_OTP_SIZE];
>> +
>> + /* True if the device has been identified */
>> + bool identified;
>> };
>>
>> static inline struct imx208 *to_imx208(struct v4l2_subdev *_sd)
>> @@ -619,6 +622,34 @@ static int imx208_set_pad_format(struct v4l2_subdev *sd,
>> return 0;
>> }
>>
>> +static int imx208_identify_module(struct imx208 *imx208)
>> +{
>> + struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
>> + int ret;
>> + u32 val;
>> +
>> + if (imx208->identified)
>> + return 0;
>
> Otp access requires this as well.
Sakari, thanks for your review.
Yes, OTP read will trigger the LED blink, but I am not sure it makes sense that camera
framework try to read the OTP data without streaming, and it would complain once fail to
access the OTP data.
>
> How about adding a runtime PM resume callback for this?
For the runtime PM callback, what is the benefit adding a callback here as will call try
pm_runtime_get_sync() each stream on?
>
> I guess it'd be better for the rest, too. Up to you.
>
>> +
>> + ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
>> + 2, &val);
>> + if (ret) {
>> + dev_err(&client->dev, "failed to read chip id %x\n",
>> + IMX208_CHIP_ID);
>> + return ret;
>> + }
>> +
>> + if (val != IMX208_CHIP_ID) {
>> + dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
>> + IMX208_CHIP_ID, val);
>> + return -EIO;
>> + }
>> +
>> + imx208->identified = true;
>> +
>> + return 0;
>> +}
>> +
>> /* Start streaming */
>> static int imx208_start_streaming(struct imx208 *imx208)
>> {
>> @@ -626,6 +657,10 @@ static int imx208_start_streaming(struct imx208 *imx208)
>> const struct imx208_reg_list *reg_list;
>> int ret, link_freq_index;
>>
>> + ret = imx208_identify_module(imx208);
>> + if (ret)
>> + return ret;
>> +
>> /* Setup PLL */
>> link_freq_index = imx208->cur_mode->link_freq_index;
>> reg_list = &link_freq_configs[link_freq_index].reg_list;
>> @@ -752,29 +787,6 @@ static int __maybe_unused imx208_resume(struct device *dev)
>> }
>>
>> /* Verify chip ID */
>> -static int imx208_identify_module(struct imx208 *imx208)
>> -{
>> - struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
>> - int ret;
>> - u32 val;
>> -
>> - ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
>> - 2, &val);
>> - if (ret) {
>> - dev_err(&client->dev, "failed to read chip id %x\n",
>> - IMX208_CHIP_ID);
>> - return ret;
>> - }
>> -
>> - if (val != IMX208_CHIP_ID) {
>> - dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
>> - IMX208_CHIP_ID, val);
>> - return -EIO;
>> - }
>> -
>> - return 0;
>> -}
>> -
>> static const struct v4l2_subdev_video_ops imx208_video_ops = {
>> .s_stream = imx208_set_stream,
>> };
>> @@ -961,6 +973,7 @@ static int imx208_probe(struct i2c_client *client)
>> {
>> struct imx208 *imx208;
>> int ret;
>> + bool full_power;
>> u32 val = 0;
>>
>> device_property_read_u32(&client->dev, "clock-frequency", &val);
>> @@ -978,11 +991,14 @@ static int imx208_probe(struct i2c_client *client)
>> /* Initialize subdev */
>> v4l2_i2c_subdev_init(&imx208->sd, client, &imx208_subdev_ops);
>>
>> - /* Check module identity */
>> - ret = imx208_identify_module(imx208);
>> - if (ret) {
>> - dev_err(&client->dev, "failed to find sensor: %d", ret);
>> - goto error_probe;
>> + full_power = acpi_dev_state_d0(&client->dev);
>> + if (full_power) {
>> + /* Check module identity */
>> + ret = imx208_identify_module(imx208);
>> + if (ret) {
>> + dev_err(&client->dev, "failed to find sensor: %d", ret);
>> + goto error_probe;
>> + }
>> }
>>
>> /* Set default mode to max resolution */
>> @@ -1017,7 +1033,9 @@ static int imx208_probe(struct i2c_client *client)
>> goto error_async_subdev;
>> }
>>
>> - pm_runtime_set_active(&client->dev);
>> + /* Set the device's state to active if it's in D0 state. */
>> + if (full_power)
>> + pm_runtime_set_active(&client->dev);
>> pm_runtime_enable(&client->dev);
>> pm_runtime_idle(&client->dev);
>>
>> @@ -1077,6 +1095,7 @@ static struct i2c_driver imx208_i2c_driver = {
>> },
>> .probe_new = imx208_probe,
>> .remove = imx208_remove,
>> + .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
>> };
>>
>> module_i2c_driver(imx208_i2c_driver);
>
--
Best regards,
Bingbu Cao
Powered by blists - more mailing lists