[ROM][5.1.1] AOSP-5.1.1 / CM-12.1 for Lenovo a2109 (20160901)

[joebine]

Oh dear, that better be a coincidence... Just for the record, what's the output of:

$ fastboot -i 0x17ef boot cwm-6.0.5.1-20160129-UNOFFICIAL-kai.img

I try that command, My PC say : downloading 'boot.img' ...
but the download never ends, it stay like that to the time I cancel the command.

Like you say PJBrs, I think this a coincidence because everything was working perfectly in KitKat. The problem happens when I notice that my battery was lo and I plug it with my charger. The tablet was ON but 2 hours later it was dead.

Look like jam97 has the same problem as mine.

I order a new mainboard for my tablet. Should be ready to try your last lollipop in a week.

 

[PJBrs]

FIRST -- A REQUEST. Please, if you read this, take a minute, start the terminal app and give the following command:

cat /sys/block/mmcblk0/device/name

and report the output here. This is why - @joebine wrote:

The problem happens when I notice that my battery was lo and I plug it with my charger. The tablet was ON but 2 hours later it was dead.

Okay. I'm still a bit worried that I haven't solved all of the problem, especially this bit:

        if (req->cmd_flags & REQ_SECURE)
                ret = mmc_blk_issue_secdiscard_rq(mq, req);
        else
                ret = mmc_blk_issue_discard_rq(mq, req);

Google has commented out the secdiscard variant. A later patch makes it conditional, and skip the call for certain types of internal memory:

        if (req->cmd_flags & REQ_SECURE &&
                !(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN))
                ret = mmc_blk_issue_secdiscard_rq(mq, req);
        else
                ret = mmc_blk_issue_discard_rq(mq, req);

Looking at the rest of the patch, it appears that the following memory types are affected:
M8G2FA, MAG4FA, MBG8FA, MCGAFA, VAL00M, VYL00M, KYL00M, and VZL00M. The evidence provided by ourselves suggests that our devices are unaffected, because our memory is MAG2GA and M8G2FB. But I can't be sure that other A2109 have other version. So please take a minute, start the terminal app and give the following command:

cat /sys/block/mmcblk0/device/name

and report the output here. THANKS!

 

[Mister X]

Great work
MAG2GA is my output

If you need another tester i will do it

 

[fusm]

Mine:
M8G2FB
Thanks!

 

[DBlake]

I've decided I'll volunteer my A2109 for testing CM12.1 since I almost never use it anyway.

 

[profeet]

Device name M8G2FB.
Get ready for testing!

 

[joebine]

I am back on tracks...

I replace the system board in my A2109 with one I bought on ebay for 15$.

The new device name is: MAG2GA
Like the old one i had.

I also bought another A2109 that is supposed to be broken and finaly is working correctly so I can make a lot of testing.

 

[johan111]

I am back on tracks...

I replace the system board in my A2109 with one I bought on ebay for 15$.

The new device name is: MAG2GA
Like the old one i had.

I also bought another A2109 that is supposed to be broken and finaly is working correctly so I can make a lot of testing.

Could you provide a link to the ebay auction where you bought the system board, please? I will consider buying a board if it is only 15$. Probably the shipping cost to Poland will be higher than the spare part itself

 

[kin-kwok]

Hi,

I believe my a2109 (16G) went into APX mode too. This is what happened.

I have been using your CM11 since summer, and normally upgrade to latest a week after you released the latest update. It was working fine but not too fast.
I am using "trimmer" every day at 3 am to auto-trim the flash.
I use waiting for the CM12.1
I have upgraded to you lastest CM11 last week that should fixed the kernel problem. It has been working fine till yesterday.
My daughter was using it to watch youtube and some video files. She complete use up the battery and it shutdown itself. BTW, it was what she told me. I was not at home.
I have recharged it last night but I cannot restart it. At one point, it showed the Lenovo logo, but nothing happen after. When I connected it to my computer, it should "apx" device and cannot find any driver.

From the last few posts, it does not look good.
Not sure what I am going to do next.

Thinking to buy a replace motherboard from ebay, but still cannot find a reasonable price one yet.......


KK

 

[joebine]

Could you provide a link to the ebay auction where you bought the system board, please? I will consider buying a board if it is only 15$. Probably the shipping cost to Poland will be higher than the spare part itself

For all of you how want to repair your A2109, this is the link on EBay for less then $15 US:

OEM Lenovo IdeaTab A2109A 9" MAINBOARD 16GB

Also, you will find all the info to open and replace the part:

Lenovo IdeaTab A2109 System Board Replacement

 

[joebine]

Looking at all the post lately, it seem like the problem that brick our devices is when we take the battery down and then try to recharge it.

I don't know what really happen to mine but it look like what happen to @kin-knok and I didn't had that broblem before I upgrade to the Kitkat ROM PJBrs made in last january.

Mabe it is just a coincidence but maybe this is something to check before further testing.

 

[PJBrs]

Hi,

I believe my a2109 (16G) went into APX mode too. This is what happened.

I have been using your CM11 since summer, and normally upgrade to latest a week after you released the latest update. It was working fine but not too fast.
I am using "trimmer" every day at 3 am to auto-trim the flash.
I use waiting for the CM12.1
I have upgraded to you lastest CM11 last week that should fixed the kernel problem. It has been working fine till yesterday.
My daughter was using it to watch youtube and some video files. She complete use up the battery and it shutdown itself. BTW, it was what she told me. I was not at home.
I have recharged it last night but I cannot restart it. At one point, it showed the Lenovo logo, but nothing happen after. When I connected it to my computer, it should "apx" device and cannot find any driver.

Hi, that's bad news, sorry to hear it! Did you try press Vol-up, Vol-down and power button simultaneously for more than 15 seconds, then release all buttons and press power button to start? I have ended up in APX mode a few times. Unfortunately, not all of us have escaped...

From the last few posts, it does not look good.
Not sure what I am going to do next.

Thinking to buy a replace motherboard from ebay, but still cannot find a reasonable price one yet.......


KK

Looking at all the post lately, it seem like the problem that brick our devices is when we take the battery down and then try to recharge it.

I don't know what really happen to mine but it look like what happen to @kin-knok and I didn't had that broblem before I upgrade to the Kitkat ROM PJBrs made in last january.

Mabe it is just a coincidence but maybe this is something to check before further testing.

Hmmm.... You know, the big problem is that I don't know what to do about this anymore. I think we have sufficiently confirmed that the MAG2GA internal memory has a firmware bug that can result in bricking, especially when fstrim is called. Then I added one patch that should have fixed it, and instead we have two bricks. So now I can do two things - either I go back to the previous, unpatched kernel, with which I appear to be the only one who had problems, or I can add three other patches to add further internal memory quirks. Please give your opinions here, while I sync my sources back to KitKat.

By the way, we have 133 new KitKat users as of now...

 

[kin-kwok]

Tried hold down the Vol+,-,Power for a minute and still no change
Tried to disconnect the battery for few hours and reconnect it back, no change

My feeling is the Oct CM11 is working batter as I have it for 3 months and never have problem. My daughter always completely drain the power of it.

KK

 

[joebine]

Hmmm.... You know, the big problem is that I don't know what to do about this anymore. I think we have sufficiently confirmed that the MAG2GA internal memory has a firmware bug that can result in bricking, especially when fstrim is called. Then I added one patch that should have fixed it, and instead we have two bricks. So now I can do two things - either I go back to the previous, unpatched kernel, with which I appear to be the only one who had problems, or I can add three other patches to add further internal memory quirks. Please give your opinions here, while I sync my sources back to KitKat.

By the way, we have 133 new KitKat users as of now...

I replace my system board and install the ROM from october in my A2109. I can try the ROM with the other patches you suggest for testing.

We have to find a way to avoid that. I have now two A2109 so I will made some testing with one of them.

Thanks for all the effort you put in that @PJBrs.

 

[PJBrs]

As I just wrote in the KitKat thread, I somehow didn't ship the right kernel, don't know what went wrong, must have messed up with git somehow, and didn't notice it before (I decided to check uname -a on my kitkat build and then did a git branch --contains {commit}. My apologies This kernel didn't include the necessary patches. I'm putting up a new build, with a patched kernel, in two days.

It might be wise to downgrade in the meantime. In any case, turn off any fstrim programmes in the meantime, and don't leave your tablet on the charger overnight, because that's when kitkat uses fstrim (If I understand correctly).