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imx: video: staging: Add HDMI support to imx-drm driver

RFC PATCH New Tony Prisk 2 participants 4 messages Aug 10, 2013 – Sep 29, 2013 2 messages not in the archive

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Tony Prisk

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#2 lore raw

RFC PATCH 1/1 imx: video: staging: Add HDMI support to imx-drm driver

Quoted 32 lines · Fabio Estevam

Hi Tony,

Quoted 11 lines · Tony Prisk

Add support for the HDMI controller found on the i.MX6. Driver is based on code originally added by Sascha Hauer, but not submitted to mainline/staging with the rest of the driver.

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This is a tidy up of Sascha's earlier HDMI driver for the staging/imx-drm driver. It is still missing CEA support, but has tested fine on a Wandboard Quad (and possibly the Dual?).

Quoted 6 lines

This is a RFC to see how people feel about the state of the code for inclusion into the mainline staging driver and what still needs to be done to get it there.

I have tidied up a lot of the unneccessary code that isn't used and added some proper OF-related stuff.

Thanks for working on this.

Quoted 6 lines

Regards
Tony Prisk

  arch/arm/boot/dts/imx6dl-wandboard.dts      |   13 +
  arch/arm/boot/dts/imx6q-wandboard.dts       |   13 +
  arch/arm/boot/dts/imx6qdl.dtsi              |   10 +

Please split the dts changes from the driver changes.

The driver changes should go via Greg Kroah-Hartman staging tree.

Quoted 8 lines

Once it is accepted, then you could submit the dts changes into Shawn's tree.

I made some comments below (mostly comestic). After you take care of them, please send a formal patch to gregkh and
devel at driverdev.osuosl.org (and also the folks you have Cc'ed here).

...

Thanks for the review.. Most of this is expected. I hadn't spent a lot of time tidying up or 'formalizing' the patch, but I will tidy up the comments you made.

Three problem's I have noticed with the driver are:

1) If I start the system with no output connected, then connect the hdmi, the framebuffer is initialized in 1024x768, but the connector/encoder is in 1920x1080 (as per the video= kernel param).

2) The PLL fails to lock several times during startup, but always seems to be ok to initialize the actually requested mode.

3) EDID reading fails occassionally for no obvious reason. Powering down the Wandboard (sometimes several times) and it comes right.

Once I get all this sorted out, and the code tidied up properly I will send a 'proper' patch.

Regards
Tony P

#3 lore raw

RFC PATCH 1/1 imx: video: staging: Add HDMI support to imx-drm driver

Hi Tony,

Quoted 10 lines · Tony Prisk

Thanks for the review.. Most of this is expected. I hadn't spent a lot of time tidying up or 'formalizing' the patch, but I will tidy up the comments you made.

Three problem's I have noticed with the driver are:

1) If I start the system with no output connected, then connect the hdmi, the framebuffer is initialized in 1024x768, but the connector/encoder is in 1920x1080 (as per the video= kernel param).

Quoted 5 lines

2) The PLL fails to lock several times during startup, but always seems to be ok to initialize the actually requested mode.

3) EDID reading fails occassionally for no obvious reason. Powering down the Wandboard (sometimes several times) and it comes right.

Could it be that the DDC pull-up resistors are out of spec on Wandboard?

According to this datasheet (Table 3) :
http://www.nxp.com/documents/data_sheet/PCA9507.pdf

the SDA/SCL pull ups should be between 1.5k - 2.0k.

On Wandboard these pullups are 2.2k.

Quoted 3 lines

Once I get all this sorted out, and the code tidied up properly I will send a 'proper' patch.

Understood.

Even though the three issues are still present, IMHO is still worth submitting your patch, as the drivers in 'staging' directory are known to be in initial development phase.

Regards,

Fabio Estevam

#4 lore raw

RFC PATCH 1/1 imx: video: staging: Add HDMI support to imx-drm driver

In reply to Tony Prisk

Hi Tony,

[Fix ARM kernel mailing list address that was wrong in your first email]

Quoted 12 lines · Tony Prisk

On 11/08/13 05:52, Fabio Estevam wrote:

Thanks for the review.. Most of this is expected. I hadn't spent a lot of time tidying up or 'formalizing' the patch, but I will tidy up the comments you made.

Three problem's I have noticed with the driver are:

1) If I start the system with no output connected, then connect the hdmi, the framebuffer is initialized in 1024x768, but the connector/encoder is in 1920x1080 (as per the video= kernel param).

Quoted 8 lines

2) The PLL fails to lock several times during startup, but always seems to be ok to initialize the actually requested mode.

3) EDID reading fails occassionally for no obvious reason. Powering down the Wandboard (sometimes several times) and it comes right.

Once I get all this sorted out, and the code tidied up properly I will send a 'proper' patch.

Do you still plan to submitting the HDMI driver for mx6?

Regards,

Fabio Estevam

author
#5 lore raw

RFC PATCH 1/1 imx: video: staging: Add HDMI support to imx-drm driver

Quoted 22 lines · Fabio Estevam

Hi Tony,

[Fix ARM kernel mailing list address that was wrong in your first email]

Quoted 17 lines · Tony Prisk

On 11/08/13 05:52, Fabio Estevam wrote:
Thanks for the review.. Most of this is expected. I hadn't spent a lot of time tidying up or 'formalizing' the patch, but I will tidy up the comments you made.

Three problem's I have noticed with the driver are:

1) If I start the system with no output connected, then connect the hdmi, the framebuffer is initialized in 1024x768, but the connector/encoder is in 1920x1080 (as per the video= kernel param).

2) The PLL fails to lock several times during startup, but always seems to be ok to initialize the actually requested mode.

3) EDID reading fails occassionally for no obvious reason. Powering down the Wandboard (sometimes several times) and it comes right.

Quoted 7 lines
Quoted 2 lines

Once I get all this sorted out, and the code tidied up properly I will send a 'proper' patch.

Do you still plan to submitting the HDMI driver for mx6?

Regards,

Fabio Estevam

Sorry... I've been tied up with work a lot lately and haven't had a lot of time to spend on it.
I still haven't been able to overcome the problem with the resolutions at 108Mhz, otherwise it seems to work pretty well. I expect it will be a while yet before I can spend any serious time on it, so if someone else wants to work through the problem and submit a patch, feel free.

Regards
Tony Prisk