On Fri, Oct 4, 2019 at 3:47 PM Pintu Agarwal pintu.ping@gmail.com wrote:
Hi,
On Sun, Sep 29, 2019 at 10:24 PM Pintu Agarwal pintu.ping@gmail.com wrote:
On Mon, Sep 23, 2019 at 1:28 PM Pintu Agarwal pintu.ping@gmail.com wrote:
Dear Philipp,
I have a iMX6dl custom board with custom Linux Kernel 4.8. I have both LCD and HDMI connected to the board. And we are using weston/wayland as the display interface. In normal boot, both LCD and HDMI display is working fine.
But, currently, for one of the requirement, I am trying to explore and support hibernation image booting on it. Currently, we are able to resume the system without display. Also, if we make the entire imx-drm as modules, and then install the modules after resume, even LCD is also coming up. But HDMI display is black out.
I just found the main root cause of the HDMI screen blackout issue after system resume.
- HDMI is trying to get EDID data from the monitor using I2C interface.
- But its seems i2c_transfer is getting timeout after 5 retries.
- Thus EDID data is failing, and HDMI could not able to detect the monitor.
This is the logs:
[ 441.104989] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:29:HDMI-A-1] status updated from unknown to connected [ 441.116080]: drm_helper_probe_single_connector_modes - inside - else override_edid [ 441.124416]: drm_helper_probe_single_connector_modes - inside - else - drm_load_edid_firmware: count: 0 [ 441.134546]: drm_helper_probe_single_connector_modes - calling - get_modes [ 441.142157]: dw_hdmi_connector_get_modes : called [ 441.147652]: dw_hdmi_connector_get_modes : called - calling -> drm_get_edid [ 441.155346]: drm_do_probe_ddc_edid : called! [ 441.660759]: drm_do_probe_ddc_edid : i2c_transfer: ret: -110, retry: 5 [ 442.170758]: drm_do_probe_ddc_edid : i2c_transfer: ret: -110, retry: 4 [ 442.680755]: drm_do_probe_ddc_edid : i2c_transfer: ret: -110, retry: 3 [ 443.190755]: drm_do_probe_ddc_edid : i2c_transfer: ret: -110, retry: 2 [ 443.700754]: drm_do_probe_ddc_edid : i2c_transfer: ret: -110, retry: 1 [ 443.707989]: drm_get_edid : called - drm_probe_ddc - failed [ 443.714303] dwhdmi-imx 120000.hdmi: failed to get edid
Is there any clue, how to resolve this i2c failure issue, after resume? This does not happen in normal booting case.
These are the steps I follow:
- Boot the system normally (without display) and install all imx-drm as modules.
- Then uninstall the modules in reverse order.
- Take the snapshot of the system (suspend to disk).
- Reboot the system and boot with the image.
- Install all the modules again.
- Then launch the Weston.
- During the weston launch in the beginning we observe this error.
* Changing the subject to be more relevant.
I need some pointers in debugging this i2c_transfer timeout issue, after system resume. I am not so much familiar with i2c, so I am looking for some clue here.
i2c-experts (or pm experts), please help me to find the root cause and debug further.
Thanks, Pintu