From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH 10/18] smc911x: pass struct device to DMA API functions Date: Fri, 1 Feb 2019 14:14:34 +0000 Message-ID: References: <20190201084801.10983-1-hch@lst.de> <20190201084801.10983-11-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190201084801.10983-11-hch@lst.de> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Christoph Hellwig , John Crispin , Vinod Koul , Dmitry Tarnyagin , Nicolas Ferre , Sudip Mukherjee , Felipe Balbi , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org, alsa-devel@alsa-project.org Cc: iommu@lists.linux-foundation.org List-Id: iommu@lists.linux-foundation.org On 01/02/2019 08:47, Christoph Hellwig wrote: > The DMA API generally relies on a struct device to work properly, and > only barely works without one for legacy reasons. Pass the easily > available struct device from the platform_device to remedy this. Hmm, as far as I'm aware these are PIO chips with external DMA handshaking, rather than actual DMA masters... > Signed-off-by: Christoph Hellwig > --- > drivers/net/ethernet/smsc/smc911x.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/smsc/smc911x.c b/drivers/net/ethernet/smsc/smc911x.c > index 8355dfbb8ec3..b550e624500d 100644 > --- a/drivers/net/ethernet/smsc/smc911x.c > +++ b/drivers/net/ethernet/smsc/smc911x.c > @@ -1188,7 +1188,7 @@ smc911x_tx_dma_irq(void *data) > > DBG(SMC_DEBUG_TX | SMC_DEBUG_DMA, dev, "TX DMA irq handler\n"); > BUG_ON(skb == NULL); > - dma_unmap_single(NULL, tx_dmabuf, tx_dmalen, DMA_TO_DEVICE); > + dma_unmap_single(lp->dev, tx_dmabuf, tx_dmalen, DMA_TO_DEVICE); ..so while the wrong device is still better than no device at all, this probably wants lp->txdma->device->dev. > netif_trans_update(dev); > dev_kfree_skb_irq(skb); > lp->current_tx_skb = NULL; > @@ -1219,7 +1219,7 @@ smc911x_rx_dma_irq(void *data) > > DBG(SMC_DEBUG_FUNC, dev, "--> %s\n", __func__); > DBG(SMC_DEBUG_RX | SMC_DEBUG_DMA, dev, "RX DMA irq handler\n"); > - dma_unmap_single(NULL, rx_dmabuf, rx_dmalen, DMA_FROM_DEVICE); > + dma_unmap_single(lp->dev, rx_dmabuf, rx_dmalen, DMA_FROM_DEVICE); And equivalently for rxdma here. However, given that this all seems only relevant to antique ARCH_PXA platforms which are presumably managing to work as-is, it's probably not worth tinkering too much. I'd just stick a note in the commit message that we're still only making these self-consistent with the existing dma_map_single() calls rather than necessarily correct. Robin. > BUG_ON(skb == NULL); > lp->current_rx_skb = NULL; > PRINT_PKT(skb->data, skb->len); >