Re: BUG: blank screen - unless keyboard/synaptic combo

From: Niel Lambrechts
Date: Thu May 21 2009 - 18:41:22 EST


On 05/19/2009 08:38 PM, Niel Lambrechts wrote:
I have a strange problem in that during a resume from hibernate my text console (or X) remains blank - that is, until I simultaneously press a keyboard key and touch the synaptic pad. It is not sufficient to press just one or the other, it needs to be done simultaneously and it resumes fine after doing this.

I have tried quite hard to overcome this issue. All of the following hibernation tests I tried involved booting into a text console, without ever starting X. With each test I still had a blank screen upon resume, and each time it was fully recoverable by pressing any keyboard key/synaptic pad touch combo.

1. Disabling a CPU core - NO CHANGE.
Based on a "multi-processor concurrency" fix mentioned on the web (Ubuntu bug #272307).

2. Upgrade BIOS to latest level - NO CHANGE.
BIOS 6FET70WW, released 04/17/2009.

3. Switching to ATI Mobility Radeon HD 3650 graphics card. NO CHANGE.
My Lenovo W500 has "switchable graphics" BIOS option, and I tried this test with both the integrated or the above-mentioned card without difference.
_This result seems quite interesting to me, as if it could be some type of bus related freeze where the keyboard/synaptic combo plays a role._

4. Disabling BIOS Options - NO CHANGE.
Enabling/disabling security chip features + TXT features.
Disabling fingerprint reader.
Disabling memory security feature.

5. Kernel options - NO CHANGE.
ACPI debugging - I enabled CONFIG_ACPI_DEBUG, but did not see any messages generated when I pressed a keyboard key + synaptic mousepad combo that recovers the console.
FIRMWARE_EDID - still testing this.

Any suggestions on anything else I could try would be most welcome...!

Thanks,
Niel

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