On Wed, 2015-05-06 at 11:25 +0100, Luis Henriques wrote: > On Tue, May 05, 2015 at 02:16:39AM +0100, Ben Hutchings wrote: > > 3.2.69-rc1 review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Andy Shevchenko <[email protected]> > > > > commit c9dafb27c84412fe4b17c3b94cc4ffeef5df1833 upstream. > > > > When DMA descriptor allocation fails we should not try to assign any fields > > in > > the bad descriptor. The patch adds the necessary checks for that. > > > > Fixes: 7063c0d942a1 (spi/dw_spi: add DMA support) > > Signed-off-by: Andy Shevchenko <[email protected]> > > Signed-off-by: Mark Brown <[email protected]> > > [bwh: Backported to 3.2: adjust context] > > Signed-off-by: Ben Hutchings <[email protected]> > > --- > > drivers/spi/spi-dw-mid.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > --- a/drivers/spi/spi-dw-mid.c > > +++ b/drivers/spi/spi-dw-mid.c > > @@ -155,6 +155,9 @@ static int mid_spi_dma_transfer(struct d > > 1, > > DMA_TO_DEVICE, > > DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP); > > + if (!txdesc) > > + return NULL; > > + > > This backport doesn't look right to me as the function returns an int, > not a pointer. OTOH, it seems like this return value is not checked > anywhere, which is why I dropped this patch in the 3.16 kernel.
In mainline the DMA descriptor setup is split out into the dw_spi_dma_prepare_tx() and dw_spi_dma_prepare_rx() functions. If they return NULL then mid_spi_dma_transfer() doesn't attempt to submit adescriptor to the respective channel, but it still returns 0. So not only is this backport pretty useless, but so is the upstream 'fix'. Ben. > Cheers, > -- > Luís > > > txdesc->callback = dw_spi_dma_done; > > txdesc->callback_param = dws; > > > > @@ -177,6 +180,9 @@ static int mid_spi_dma_transfer(struct d > > 1, > > DMA_FROM_DEVICE, > > DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP); > > + if (!rxdesc) > > + return NULL; > > + > > rxdesc->callback = dw_spi_dma_done; > > rxdesc->callback_param = dws; > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe stable" in > > the body of a message to [email protected] > > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Ben Hutchings If at first you don't succeed, you're doing about average.
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