On Mon, 2016-06-13 at 21:59 -0500, Dinh Nguyen wrote: > Apologies, but my original email bounced for Andy and Heikki, > resending. > ---- I suppose this one, i.e. commit dd4e91d538b3 ("dmaengine: slave means at least one of DMA_SLAVE, DMA_CYCLIC"), solves the issue. > > Hi Andy, > > I saw that you have discovered that commit ec5a11a91eec ("serial: > 8250: > Validate dmaengine rx chan meets requirements") introduced a > regression > in the 8250 uart driver. For SoCFPGA platform, I am seeing this error: > > [ 5.541751] ttyS0 - failed to request DMA > > Reverting the commit ec5a11a91eec removes the error. > > I saw that you started the discussion, but I didn't see that a patch > was > included[1]. > > The following patch seems to fix the error, but I'm not sure if it's > the > same fix that you had in mind. > > Thanks, > Dinh > > [1] http://marc.info/?l=linux-serial&m=146254187602862&w=2 > > ---------------8<------------ > diff --git a/drivers/tty/serial/8250/8250_dma.c > b/drivers/tty/serial/8250/8250_dma.c > index 7f33d1c..847a203 100644 > --- a/drivers/tty/serial/8250/8250_dma.c > +++ b/drivers/tty/serial/8250/8250_dma.c > @@ -176,7 +176,7 @@ int serial8250_request_dma(struct uart_8250_port > *p) > ret = dma_get_slave_caps(dma->rxchan, &caps); > if (ret) > goto release_rx; > - if (!caps.cmd_pause || !caps.cmd_terminate || > + if ((!caps.cmd_pause || !caps.cmd_terminate) && > caps.residue_granularity == > DMA_RESIDUE_GRANULARITY_DESCRIPTOR) { > ret = -EINVAL; > goto release_rx; -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html