What does imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_10 mean?

[dv1]

Hello,

I am running an i.MX6DL Sabre SD board with Yocto, using kernel 3.0.35 from meta-fsl-arm/recipes-kernel/linux at master · Freescale/meta-fsl-arm · GitHub (which in turn gets the kernel sources from git://git.freescale.com/imx/linux-2.6-imx.git ) , and it works just fine. However, I do see the following warnings sometimes:

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_10 = 0x00100000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08800000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_10 = 0x00100000

What do these warnings mean? Should I be alarmed? Can I safely ignore them? (I got these after running both a video and an OpenGL ES 2 3D rendering at the same time.)

[Yuri · Accepted solution]

According to the i.MX6(Q) Reference Manual :

IPU_INT_STAT_10 = 0x00100000 means synchronous display error interrupt,

as a result of an error during access to a synchronous display.

IPU_INT_STAT_5 = 0x08800000 means, that new frame starts before the previous

end-of-frame event.

   Next, from section 38.4.12.3 (Interrupt Generator) of the Reference Manual :

“The table below describes the error interrupts. The panic column indicates if this signal is

part of the logic generating the ipu_panic signal. The ipu_panic signal can be used for

indicating about errors that are result of data rate problems. Such problems may be a

result of the IPU running in slower clock then required by the use case. This signal can be

used in order to indicate the system that the IPU can't handle the desired data rate. In that

case the system may need to increase the clock to the IPU or simplify the use case.”

   So, we have here performance problem. Please try to decrease screen resolution and / or

frame rate. Also, other system resource consuming processes, such as USB / SD / SATA

transfer, may affect. As result a general performance issue may take place in the case.

Perhaps it makes sense to try system prioritization (such as provided by Linux nice

command).