fsl espi controller report interrupt frequently

[qingshanli]

When p1020 access switch chip by espi interface, sometimes it reports interrupt frequently about 100,000 times per second, and the spi controller can't work normally.

We dump the espi register as below:

0xffe07000      0x80000403

0xffe07004      0x0020e900

0xffe07008      0x00000000

0xffe0700c      0x00000000

0xffe07010      0x00000000

0xffe07014      0xffffffff

0xffe07018      0x00000000

0xffe0701c      0x00000000

So it seems the espi controller enter into an abnormal situation. How can I fix it?

[alexander_yakov · Accepted solution]

Please make sure SPIE register is always cleared before returning from interrupt handler.

The dump you submitted shows the situation where RXT=1 while RNE=0, that means RXT bit was not cleared by software.

Please let me remind, RXT bit is sticky bit, it must be cleared explicitly by user software by writing "1" to it.

Have a great day,
Alexander
TIC

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[qingshanli]

Here use  linux-2.6.35