Re: [PATCH V6 08/10] USB: f81232: fix read MSR strange value

From: Peter Hung
Date: Mon Feb 23 2015 - 21:17:16 EST


Johan Hovold æ 2015/2/17 äå 05:51 åé:

So we add more check not only UART_MSR_ANY_DELTA but also with
comparing DCD/RI/DSR/CTS change with old value. Due to the state
bit is always correct, we direct save msr when read.

The following step to reproduce this problem with while loop step 1~4:
1. ioctl(fd, TIOCMSET, &data) to set RTS or DTR
2. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state
3. ioctl(fd, TIOCMSET, &data) to unset RTS or DTR
4. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state

Without having looked at this very closely; are you sure this is a
hardware issue and not related to the locking issues I pointed at in my
comments to tiocmset?


Thank for your review.

I'll apply all suggestions to next v7 patch.

With Best Regards,
Peter Hung
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