tree cf7bc9402cb3c3637ea8797179d33d0995509470
parent 7b39d901846d2548829e7788eefcfe9091224973
author Geert Uytterhoeven <geert+renesas@glider.be> 1440180175 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1443976428 +0100

serial: sh-sci: Don't call sci_rx_interrupt() on error when using DMA

The error handler calls sci_rx_interrupt() to drain the receive FIFO if
an error condition happens.

However, if DMA is enabled on SCIFA or SCIFB, this will call
disable_irq_nosync() twice. Due to this imbalance, the receive interrupt
will never be re-enabled, and reception stops forever.

To fix this, restrict draining the FIFO to PIO mode, and just call
sci_receive_chars() directly.

Inspired by a patch from Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com>.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>