[PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[Jason Yang via B4 Relay]

From: Jason Yang <jason98166@gmail.com>

ov5640_set_stream_mipi() always programs IO_MIPI_CTRL00 with 0x45,
which selects the two data lane mode: the number of data lanes
described in the devicetree endpoint only feeds the sensor's clock
tree computations, so a module wired with one data lane starts
streaming in two lane mode and the receiver never assembles a
frame.

Take the lane mode from the endpoint instead. The field encodes
the lane count directly - 001 for one lane, 010 for two - per the
current sensor manual (version 2.33). The 2.03 manual documented
000/001 for one/two lanes; OmniVision corrected the table in
version 2.1, which is why the long-standing comment here found 001
unusable for two lanes and validated 010 instead.

The power-up path also programs a two data lane mode, but that
value is overwritten when streaming starts, so it is left alone.

Tested with a single data lane module on an i.MX8MP board
(imx-mipi-csis receiver), where the unpatched value produces no
frames at all, and on an RK3588 board.

Fixes: 19a81c1426c1 ("[media] add Omnivision OV5640 sensor driver")
Cc: stable@vger.kernel.org
Signed-off-by: Jason Yang <jason98166@gmail.com>
Assisted-by: Claude:claude-opus-5
---
Changes in v4:
- Keep the lane count programmed also while the interface is
  disabled, toggling only the enable bits (Hans Verkuil); with one
  data lane the disable value becomes 0x20 instead of 0x40.
- Link to v3: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v3-1-ae476eaf5024@gmail.com

Changes in v3:
- Inline the lane count in the write instead of going through a
  local variable (Sakari Ailus).
- Link to v2: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v2-1-65205ae86feb@gmail.com

Changes in v2:
- Compute the register value from the lane count in the single
  write instead of branching on it (Sakari Ailus), with the count
  in a local variable to stay within 80 columns; the programmed
  values are unchanged, 0x25 for one lane and 0x45 for two.
- Request a normal stable backport rather than opting out of
  AUTOSEL (Sakari Ailus).
- Drop the quotes around the function name in the reference from
  ov5640_set_power_mipi() (Sakari Ailus).
- Link to v1: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v1-1-79699457ce13@gmail.com
---
 drivers/media/i2c/ov5640.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 8deb5f5501fa..a99e4edb6a75 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -1831,22 +1831,16 @@ static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
 	/*
 	 * Enable/disable the MIPI interface
 	 *
-	 * 0x300e = on ? 0x45 : 0x40
-	 *
-	 * FIXME: the sensor manual (version 2.03) reports
-	 * [7:5] = 000  : 1 data lane mode
-	 * [7:5] = 001  : 2 data lanes mode
-	 * But this settings do not work, while the following ones
-	 * have been validated for 2 data lanes mode.
-	 *
-	 * [7:5] = 010	: 2 data lanes mode
+	 * [7:5]	: data lane count, 001 for one lane and 010 for two,
+	 *		  per version 2.33 of the sensor manual
 	 * [4] = 0	: Power up MIPI HS Tx
 	 * [3] = 0	: Power up MIPI LS Rx
 	 * [2] = 1/0	: MIPI interface enable/disable
 	 * [1:0] = 01/00: FIXME: 'debug'
 	 */
 	ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00,
-			       on ? 0x45 : 0x40);
+			       sensor->ep.bus.mipi_csi2.num_data_lanes << 5 |
+			       (on ? 0x05 : 0x0));
 	if (ret)
 		return ret;
 
@@ -2535,8 +2529,8 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
 	 * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
 	 *
 	 * 0x300e = 0x40
-	 * [7:5] = 010	: 2 data lanes mode (see FIXME note in
-	 *		  "ov5640_set_stream_mipi()")
+	 * [7:5] = 010	: 2 data lanes mode (see the note in
+	 *		  ov5640_set_stream_mipi())
 	 * [4] = 0	: Power up MIPI HS Tx
 	 * [3] = 0	: Power up MIPI LS Rx
 	 * [2] = 1	: MIPI interface enabled

---
base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
change-id: 20260811-ov5640-1lane-v1-b0fe37eab4d8

Best regards,
-- 
Jason Yang <jason98166@gmail.com>

Re: [PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[johannes.goede]

Hi,

On 11-Aug-26 11:17, Jason Yang via B4 Relay wrote:
> From: Jason Yang <jason98166@gmail.com>
> 
> ov5640_set_stream_mipi() always programs IO_MIPI_CTRL00 with 0x45,
> which selects the two data lane mode: the number of data lanes
> described in the devicetree endpoint only feeds the sensor's clock
> tree computations, so a module wired with one data lane starts
> streaming in two lane mode and the receiver never assembles a
> frame.
> 
> Take the lane mode from the endpoint instead. The field encodes
> the lane count directly - 001 for one lane, 010 for two - per the
> current sensor manual (version 2.33). The 2.03 manual documented
> 000/001 for one/two lanes; OmniVision corrected the table in
> version 2.1, which is why the long-standing comment here found 001
> unusable for two lanes and validated 010 instead.
> 
> The power-up path also programs a two data lane mode, but that
> value is overwritten when streaming starts, so it is left alone.
> 
> Tested with a single data lane module on an i.MX8MP board
> (imx-mipi-csis receiver), where the unpatched value produces no
> frames at all, and on an RK3588 board.
> 
> Fixes: 19a81c1426c1 ("[media] add Omnivision OV5640 sensor driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jason Yang <jason98166@gmail.com>
> Assisted-by: Claude:claude-opus-5
> ---
> Changes in v4:
> - Keep the lane count programmed also while the interface is
>   disabled, toggling only the enable bits (Hans Verkuil); with one
>   data lane the disable value becomes 0x20 instead of 0x40.

Erm, I know having 2 Hans' in linux-media is confusing but I'm
not Hans Verkuil, I'm the other Hans :)

No problem and no need for a v5 since the changelog will get
cut anyways.

Regards,

Hans



> - Link to v3: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v3-1-ae476eaf5024@gmail.com
> 
> Changes in v3:
> - Inline the lane count in the write instead of going through a
>   local variable (Sakari Ailus).
> - Link to v2: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v2-1-65205ae86feb@gmail.com
> 
> Changes in v2:
> - Compute the register value from the lane count in the single
>   write instead of branching on it (Sakari Ailus), with the count
>   in a local variable to stay within 80 columns; the programmed
>   values are unchanged, 0x25 for one lane and 0x45 for two.
> - Request a normal stable backport rather than opting out of
>   AUTOSEL (Sakari Ailus).
> - Drop the quotes around the function name in the reference from
>   ov5640_set_power_mipi() (Sakari Ailus).
> - Link to v1: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v1-1-79699457ce13@gmail.com
> ---
>  drivers/media/i2c/ov5640.c | 18 ++++++------------
>  1 file changed, 6 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 8deb5f5501fa..a99e4edb6a75 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -1831,22 +1831,16 @@ static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
>  	/*
>  	 * Enable/disable the MIPI interface
>  	 *
> -	 * 0x300e = on ? 0x45 : 0x40
> -	 *
> -	 * FIXME: the sensor manual (version 2.03) reports
> -	 * [7:5] = 000  : 1 data lane mode
> -	 * [7:5] = 001  : 2 data lanes mode
> -	 * But this settings do not work, while the following ones
> -	 * have been validated for 2 data lanes mode.
> -	 *
> -	 * [7:5] = 010	: 2 data lanes mode
> +	 * [7:5]	: data lane count, 001 for one lane and 010 for two,
> +	 *		  per version 2.33 of the sensor manual
>  	 * [4] = 0	: Power up MIPI HS Tx
>  	 * [3] = 0	: Power up MIPI LS Rx
>  	 * [2] = 1/0	: MIPI interface enable/disable
>  	 * [1:0] = 01/00: FIXME: 'debug'
>  	 */
>  	ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00,
> -			       on ? 0x45 : 0x40);
> +			       sensor->ep.bus.mipi_csi2.num_data_lanes << 5 |
> +			       (on ? 0x05 : 0x0));
>  	if (ret)
>  		return ret;
>  
> @@ -2535,8 +2529,8 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
>  	 * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
>  	 *
>  	 * 0x300e = 0x40
> -	 * [7:5] = 010	: 2 data lanes mode (see FIXME note in
> -	 *		  "ov5640_set_stream_mipi()")
> +	 * [7:5] = 010	: 2 data lanes mode (see the note in
> +	 *		  ov5640_set_stream_mipi())
>  	 * [4] = 0	: Power up MIPI HS Tx
>  	 * [3] = 0	: Power up MIPI LS Rx
>  	 * [2] = 1	: MIPI interface enabled
> 
> ---
> base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
> change-id: 20260811-ov5640-1lane-v1-b0fe37eab4d8
> 
> Best regards,

Re: [PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[johannes.goede]

Hi,

On 11-Aug-26 11:17, Jason Yang via B4 Relay wrote:
> From: Jason Yang <jason98166@gmail.com>
> 
> ov5640_set_stream_mipi() always programs IO_MIPI_CTRL00 with 0x45,
> which selects the two data lane mode: the number of data lanes
> described in the devicetree endpoint only feeds the sensor's clock
> tree computations, so a module wired with one data lane starts
> streaming in two lane mode and the receiver never assembles a
> frame.
> 
> Take the lane mode from the endpoint instead. The field encodes
> the lane count directly - 001 for one lane, 010 for two - per the
> current sensor manual (version 2.33). The 2.03 manual documented
> 000/001 for one/two lanes; OmniVision corrected the table in
> version 2.1, which is why the long-standing comment here found 001
> unusable for two lanes and validated 010 instead.
> 
> The power-up path also programs a two data lane mode, but that
> value is overwritten when streaming starts, so it is left alone.
> 
> Tested with a single data lane module on an i.MX8MP board
> (imx-mipi-csis receiver), where the unpatched value produces no
> frames at all, and on an RK3588 board.
> 
> Fixes: 19a81c1426c1 ("[media] add Omnivision OV5640 sensor driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jason Yang <jason98166@gmail.com>
> Assisted-by: Claude:claude-opus-5
> ---
> Changes in v4:
> - Keep the lane count programmed also while the interface is
>   disabled, toggling only the enable bits (Hans Verkuil); with one
>   data lane the disable value becomes 0x20 instead of 0x40.
> - Link to v3: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v3-1-ae476eaf5024@gmail.com
> 
> Changes in v3:
> - Inline the lane count in the write instead of going through a
>   local variable (Sakari Ailus).
> - Link to v2: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v2-1-65205ae86feb@gmail.com
> 
> Changes in v2:
> - Compute the register value from the lane count in the single
>   write instead of branching on it (Sakari Ailus), with the count
>   in a local variable to stay within 80 columns; the programmed
>   values are unchanged, 0x25 for one lane and 0x45 for two.
> - Request a normal stable backport rather than opting out of
>   AUTOSEL (Sakari Ailus).
> - Drop the quotes around the function name in the reference from
>   ov5640_set_power_mipi() (Sakari Ailus).
> - Link to v1: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v1-1-79699457ce13@gmail.com
> ---
>  drivers/media/i2c/ov5640.c | 18 ++++++------------
>  1 file changed, 6 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 8deb5f5501fa..a99e4edb6a75 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -1831,22 +1831,16 @@ static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
>  	/*
>  	 * Enable/disable the MIPI interface
>  	 *
> -	 * 0x300e = on ? 0x45 : 0x40
> -	 *
> -	 * FIXME: the sensor manual (version 2.03) reports
> -	 * [7:5] = 000  : 1 data lane mode
> -	 * [7:5] = 001  : 2 data lanes mode
> -	 * But this settings do not work, while the following ones
> -	 * have been validated for 2 data lanes mode.
> -	 *
> -	 * [7:5] = 010	: 2 data lanes mode
> +	 * [7:5]	: data lane count, 001 for one lane and 010 for two,
> +	 *		  per version 2.33 of the sensor manual
>  	 * [4] = 0	: Power up MIPI HS Tx
>  	 * [3] = 0	: Power up MIPI LS Rx
>  	 * [2] = 1/0	: MIPI interface enable/disable
>  	 * [1:0] = 01/00: FIXME: 'debug'
>  	 */
>  	ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00,
> -			       on ? 0x45 : 0x40);
> +			       sensor->ep.bus.mipi_csi2.num_data_lanes << 5 |
> +			       (on ? 0x05 : 0x0));
>  	if (ret)
>  		return ret;
>  
> @@ -2535,8 +2529,8 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
>  	 * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
>  	 *
>  	 * 0x300e = 0x40
> -	 * [7:5] = 010	: 2 data lanes mode (see FIXME note in
> -	 *		  "ov5640_set_stream_mipi()")
> +	 * [7:5] = 010	: 2 data lanes mode (see the note in
> +	 *		  ov5640_set_stream_mipi())
>  	 * [4] = 0	: Power up MIPI HS Tx
>  	 * [3] = 0	: Power up MIPI LS Rx
>  	 * [2] = 1	: MIPI interface enabled

Sorry that I missed this previously, but should this not also
write the correct lane-count right away, rather then waiting
with fixing the line-count for 1 lane configs till we hit
ov5640_set_stream_mipi() ?

Regards,

Hans

Re: [PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[楊智成]

Hi Hans,

Sorry about the name mix-up. I'll make sure to credit this to Hans de

Goede in the next version.

> Sorry that I missed this previously, but should this not also

> write the correct lane-count right away, rather then waiting

> with fixing the line-count for 1 lane configs till we hit

> ov5640_set_stream_mipi() ?

I intentionally kept the fix to the streaming path. The value written

during power-up is overwritten when streaming starts, before any frames

are produced, so it should not affect the actual stream. I also wanted

to keep the Fixes: patch as minimal as possible to make backporting

easier.

Would you prefer me to extend the patch to program the correct lane

count during power-up as well?

Regards,

Jason


<johannes.goede@oss.qualcomm.com> 於 2026年8月11日週二 下午7:10寫道：
>
> Hi,
>
> On 11-Aug-26 11:17, Jason Yang via B4 Relay wrote:
> > From: Jason Yang <jason98166@gmail.com>
> >
> > ov5640_set_stream_mipi() always programs IO_MIPI_CTRL00 with 0x45,
> > which selects the two data lane mode: the number of data lanes
> > described in the devicetree endpoint only feeds the sensor's clock
> > tree computations, so a module wired with one data lane starts
> > streaming in two lane mode and the receiver never assembles a
> > frame.
> >
> > Take the lane mode from the endpoint instead. The field encodes
> > the lane count directly - 001 for one lane, 010 for two - per the
> > current sensor manual (version 2.33). The 2.03 manual documented
> > 000/001 for one/two lanes; OmniVision corrected the table in
> > version 2.1, which is why the long-standing comment here found 001
> > unusable for two lanes and validated 010 instead.
> >
> > The power-up path also programs a two data lane mode, but that
> > value is overwritten when streaming starts, so it is left alone.
> >
> > Tested with a single data lane module on an i.MX8MP board
> > (imx-mipi-csis receiver), where the unpatched value produces no
> > frames at all, and on an RK3588 board.
> >
> > Fixes: 19a81c1426c1 ("[media] add Omnivision OV5640 sensor driver")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Jason Yang <jason98166@gmail.com>
> > Assisted-by: Claude:claude-opus-5
> > ---
> > Changes in v4:
> > - Keep the lane count programmed also while the interface is
> >   disabled, toggling only the enable bits (Hans Verkuil); with one
> >   data lane the disable value becomes 0x20 instead of 0x40.
> > - Link to v3: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v3-1-ae476eaf5024@gmail.com
> >
> > Changes in v3:
> > - Inline the lane count in the write instead of going through a
> >   local variable (Sakari Ailus).
> > - Link to v2: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v2-1-65205ae86feb@gmail.com
> >
> > Changes in v2:
> > - Compute the register value from the lane count in the single
> >   write instead of branching on it (Sakari Ailus), with the count
> >   in a local variable to stay within 80 columns; the programmed
> >   values are unchanged, 0x25 for one lane and 0x45 for two.
> > - Request a normal stable backport rather than opting out of
> >   AUTOSEL (Sakari Ailus).
> > - Drop the quotes around the function name in the reference from
> >   ov5640_set_power_mipi() (Sakari Ailus).
> > - Link to v1: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v1-1-79699457ce13@gmail.com
> > ---
> >  drivers/media/i2c/ov5640.c | 18 ++++++------------
> >  1 file changed, 6 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > index 8deb5f5501fa..a99e4edb6a75 100644
> > --- a/drivers/media/i2c/ov5640.c
> > +++ b/drivers/media/i2c/ov5640.c
> > @@ -1831,22 +1831,16 @@ static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
> >       /*
> >        * Enable/disable the MIPI interface
> >        *
> > -      * 0x300e = on ? 0x45 : 0x40
> > -      *
> > -      * FIXME: the sensor manual (version 2.03) reports
> > -      * [7:5] = 000  : 1 data lane mode
> > -      * [7:5] = 001  : 2 data lanes mode
> > -      * But this settings do not work, while the following ones
> > -      * have been validated for 2 data lanes mode.
> > -      *
> > -      * [7:5] = 010  : 2 data lanes mode
> > +      * [7:5]        : data lane count, 001 for one lane and 010 for two,
> > +      *                per version 2.33 of the sensor manual
> >        * [4] = 0      : Power up MIPI HS Tx
> >        * [3] = 0      : Power up MIPI LS Rx
> >        * [2] = 1/0    : MIPI interface enable/disable
> >        * [1:0] = 01/00: FIXME: 'debug'
> >        */
> >       ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00,
> > -                            on ? 0x45 : 0x40);
> > +                            sensor->ep.bus.mipi_csi2.num_data_lanes << 5 |
> > +                            (on ? 0x05 : 0x0));
> >       if (ret)
> >               return ret;
> >
> > @@ -2535,8 +2529,8 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
> >        * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
> >        *
> >        * 0x300e = 0x40
> > -      * [7:5] = 010  : 2 data lanes mode (see FIXME note in
> > -      *                "ov5640_set_stream_mipi()")
> > +      * [7:5] = 010  : 2 data lanes mode (see the note in
> > +      *                ov5640_set_stream_mipi())
> >        * [4] = 0      : Power up MIPI HS Tx
> >        * [3] = 0      : Power up MIPI LS Rx
> >        * [2] = 1      : MIPI interface enabled
>
> Sorry that I missed this previously, but should this not also
> write the correct lane-count right away, rather then waiting
> with fixing the line-count for 1 lane configs till we hit
> ov5640_set_stream_mipi() ?
>
> Regards,
>
> Hans
>
>

Re: [PATCH v4] media: ov5640: select the MIPI lane mode from the endpoint lane count

[johannes.goede]

Hi Jason,

On 11-Aug-26 14:32, 楊智成 wrote:
> Hi Hans,
> 
> Sorry about the name mix-up. I'll make sure to credit this to Hans de
> Goede in the next version.
> 
>> Sorry that I missed this previously, but should this not also
>> write the correct lane-count right away, rather then waiting
>> with fixing the line-count for 1 lane configs till we hit
> 
>> ov5640_set_stream_mipi() ?
> 
> I intentionally kept the fix to the streaming path. The value written
> during power-up is overwritten when streaming starts, before any frames
> are produced, so it should not affect the actual stream. I also wanted
> to keep the Fixes: patch as minimal as possible to make backporting
> easier.
> 
> Would you prefer me to extend the patch to program the correct lane
> count during power-up as well?

Yes please, since the FIXME comment was present in both places it
seems consistent to me to also actually fix the issue in both places.

Regards,

Hans






> <johannes.goede@oss.qualcomm.com> 於 2026年8月11日週二 下午7:10寫道：
>>
>> Hi,
>>
>> On 11-Aug-26 11:17, Jason Yang via B4 Relay wrote:
>>> From: Jason Yang <jason98166@gmail.com>
>>>
>>> ov5640_set_stream_mipi() always programs IO_MIPI_CTRL00 with 0x45,
>>> which selects the two data lane mode: the number of data lanes
>>> described in the devicetree endpoint only feeds the sensor's clock
>>> tree computations, so a module wired with one data lane starts
>>> streaming in two lane mode and the receiver never assembles a
>>> frame.
>>>
>>> Take the lane mode from the endpoint instead. The field encodes
>>> the lane count directly - 001 for one lane, 010 for two - per the
>>> current sensor manual (version 2.33). The 2.03 manual documented
>>> 000/001 for one/two lanes; OmniVision corrected the table in
>>> version 2.1, which is why the long-standing comment here found 001
>>> unusable for two lanes and validated 010 instead.
>>>
>>> The power-up path also programs a two data lane mode, but that
>>> value is overwritten when streaming starts, so it is left alone.
>>>
>>> Tested with a single data lane module on an i.MX8MP board
>>> (imx-mipi-csis receiver), where the unpatched value produces no
>>> frames at all, and on an RK3588 board.
>>>
>>> Fixes: 19a81c1426c1 ("[media] add Omnivision OV5640 sensor driver")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Jason Yang <jason98166@gmail.com>
>>> Assisted-by: Claude:claude-opus-5
>>> ---
>>> Changes in v4:
>>> - Keep the lane count programmed also while the interface is
>>>   disabled, toggling only the enable bits (Hans Verkuil); with one
>>>   data lane the disable value becomes 0x20 instead of 0x40.
>>> - Link to v3: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v3-1-ae476eaf5024@gmail.com
>>>
>>> Changes in v3:
>>> - Inline the lane count in the write instead of going through a
>>>   local variable (Sakari Ailus).
>>> - Link to v2: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v2-1-65205ae86feb@gmail.com
>>>
>>> Changes in v2:
>>> - Compute the register value from the lane count in the single
>>>   write instead of branching on it (Sakari Ailus), with the count
>>>   in a local variable to stay within 80 columns; the programmed
>>>   values are unchanged, 0x25 for one lane and 0x45 for two.
>>> - Request a normal stable backport rather than opting out of
>>>   AUTOSEL (Sakari Ailus).
>>> - Drop the quotes around the function name in the reference from
>>>   ov5640_set_power_mipi() (Sakari Ailus).
>>> - Link to v1: https://lore.kernel.org/r/20260811-ov5640-1lane-v1-v1-1-79699457ce13@gmail.com
>>> ---
>>>  drivers/media/i2c/ov5640.c | 18 ++++++------------
>>>  1 file changed, 6 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
>>> index 8deb5f5501fa..a99e4edb6a75 100644
>>> --- a/drivers/media/i2c/ov5640.c
>>> +++ b/drivers/media/i2c/ov5640.c
>>> @@ -1831,22 +1831,16 @@ static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
>>>       /*
>>>        * Enable/disable the MIPI interface
>>>        *
>>> -      * 0x300e = on ? 0x45 : 0x40
>>> -      *
>>> -      * FIXME: the sensor manual (version 2.03) reports
>>> -      * [7:5] = 000  : 1 data lane mode
>>> -      * [7:5] = 001  : 2 data lanes mode
>>> -      * But this settings do not work, while the following ones
>>> -      * have been validated for 2 data lanes mode.
>>> -      *
>>> -      * [7:5] = 010  : 2 data lanes mode
>>> +      * [7:5]        : data lane count, 001 for one lane and 010 for two,
>>> +      *                per version 2.33 of the sensor manual
>>>        * [4] = 0      : Power up MIPI HS Tx
>>>        * [3] = 0      : Power up MIPI LS Rx
>>>        * [2] = 1/0    : MIPI interface enable/disable
>>>        * [1:0] = 01/00: FIXME: 'debug'
>>>        */
>>>       ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00,
>>> -                            on ? 0x45 : 0x40);
>>> +                            sensor->ep.bus.mipi_csi2.num_data_lanes << 5 |
>>> +                            (on ? 0x05 : 0x0));
>>>       if (ret)
>>>               return ret;
>>>
>>> @@ -2535,8 +2529,8 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
>>>        * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
>>>        *
>>>        * 0x300e = 0x40
>>> -      * [7:5] = 010  : 2 data lanes mode (see FIXME note in
>>> -      *                "ov5640_set_stream_mipi()")
>>> +      * [7:5] = 010  : 2 data lanes mode (see the note in
>>> +      *                ov5640_set_stream_mipi())
>>>        * [4] = 0      : Power up MIPI HS Tx
>>>        * [3] = 0      : Power up MIPI LS Rx
>>>        * [2] = 1      : MIPI interface enabled
>>
>> Sorry that I missed this previously, but should this not also
>> write the correct lane-count right away, rather then waiting
>> with fixing the line-count for 1 lane configs till we hit
>> ov5640_set_stream_mipi() ?
>>
>> Regards,
>>
>> Hans
>>
>>