diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2019-01-07 19:23:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-08 18:56:52 +0300 |
| commit | 26f073993665683f1debf4d66d8bc274ac6df771 (patch) | |
| tree | 8cbd15adf833abe95d482de95a0ace3bf28265b7 /drivers/tty/serial/sh-sci.c | |
| parent | 38766e4b612ba10844afadf2fce12f8f90465c64 (diff) | |
| download | linux-26f073993665683f1debf4d66d8bc274ac6df771.tar.xz | |
serial: sh-sci: Fix fallback to PIO in sci_dma_rx_complete()
When submitting a DMA request fails in sci_dma_rx_complete(), the driver
tries to fall back to PIO, but that does not work: no more data will be
received, or the kernel will even crash.
Fix this similar as in (but not identical to) sci_submit_rx():
- On SCIF, PIO cannot take over if any DMA transactions are pending,
hence they must be terminated first.
- All active cookies must be invalidated, else rx_timer_fn() may
trigger a NULL pointer dereference.
- Restarting the port is not needed, as it is already running, but
serial port interrupts must be directed back from the DMA engine to
the CPU.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 4d814c30c418..891833315698 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1337,8 +1337,9 @@ fail: dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); /* Switch to PIO */ spin_lock_irqsave(&port->lock, flags); - s->chan_rx = NULL; - sci_start_rx(port); + dmaengine_terminate_async(chan); + sci_dma_rx_chan_invalidate(s); + sci_dma_rx_reenable_irq(s); spin_unlock_irqrestore(&port->lock, flags); } |