Daer Sir,
I'm very sorry to trouble you.
Recently I found the uart2 at csr primaII platform can't work
well after the system goto standby and then resume.
My test environment is as follows：
kernel: 3.10.16
cpu: csr primaII
My test process is as follows :
1> create a thread ,looped transmit data via uart2 every 3s.
2>primaII goto standby mode.
3>primaII goto resume.
4>capture the data at uart2 tx pin by the logic analyzer. you will
found the data is error.
for example when looped send a test frame : 5A A5 05 FA 1A 00 00
00 05 E2 A3 3A AA 55 77
you will got : 5A A5 1A 00 00 00 05 E2 A3 3A AA 55 5C E0 77
or 5A A5 05 00 00 00 05 E2 A3 3A AA 55 77 E8 8B
the result is not fixed.
I also tried some tests as follows:
1> looped send data and do not goto standby, the result is right.
2> disable the uart2 dma at prima2.dtsi, the result is right.
3> when the frame length is 4*n, the result is right. (for example
16, 20,24)
I also add some log at sirfsoc_uart.c:
print the xmit buffer at sirfsoc_uart_pio_rx_chars and
sirfsoc_uart_tx_with_dma.
I found the data is right at uart driver. I also found that the
wrong data is transmitted by the dma.
Thank you.
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