UART2 No Rx data with Android R10.4 worked perfectly on R9.2! What happened?

[mbp]

Updated from R9.2 to R10.4 on Mx51-BBG system.  Used UART2 (ttymxc1) for serial communication to proprietary HW.  Tx works fine but absolutely no Rx. 

Analysis indicates that ttymxc1 is now owned by gps - where in 9.2 it was bluetooth, not sure this means diddly-squat.  mx51_babbage.c file calls correct IOMUX from all I can see.

Not sure if this is a Kernel or Android issue or some service is grabbing the incoming data so my app sees nothing....

Been beating on this for several days :smileyconfused: and hope that someone out there has encountered a similar issue and could point the way.

HELP!  

thanks :smileyhappy:

[mbp · Accepted solution]

Solved! 

...required an iomux definition tweak in the Kernel.

[normancheung]

Mike,

Could you please share what is the IOMUX tweak?  I am running ito the same problem.

Thanks,

Norm

[mbp]

Norman,

Without booting my Linux system, I believe this is the patch.  LEt me know if it doesn't fix it.

In ../arch/arm/plat-mxc/include/mach/iomux-mx51.h:

-  #define _MX51_PAD_UART2_TXD__UART2_TXD IOMUX_PAD(0x62c, 0x23c, 0, 0x09ec, 3, 0)

+ #define _MX51_PAD_UART2_TXD__UART2_TXD IOMUX_PAD(0x62c, 0x23c, 0, 0x0000, 0, 0)

Mike