From 7b81cb6bddd2c4f2489506771070924bd0ae9902 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 16 Aug 2019 08:24:32 +0200 Subject: usb: add a HCD_DMA flag instead of guestimating DMA capabilities The usb core is the only major place in the kernel that checks for a non-NULL device dma_mask to see if a device is DMA capable. This is generally a bad idea, as all major busses always set up a DMA mask, even if the device is not DMA capable - in fact bus layers like PCI can't even know if a device is DMA capable at enumeration time. This leads to lots of workaround in HCD drivers, and also prevented us from setting up a DMA mask for platform devices by default last time we tried. Replace this guess with an explicit HCD_DMA that is set by drivers that appear to have DMA support. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20190816062435.881-4-hch@lst.de Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/isp1362-hcd.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers/usb/host/isp1362-hcd.c') diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c index 28bf8bfb091e..96f8daa11f25 100644 --- a/drivers/usb/host/isp1362-hcd.c +++ b/drivers/usb/host/isp1362-hcd.c @@ -2645,11 +2645,6 @@ static int isp1362_probe(struct platform_device *pdev) if (pdev->num_resources < 3) return -ENODEV; - if (pdev->dev.dma_mask) { - DBG(1, "won't do DMA"); - return -ENODEV; - } - irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!irq_res) return -ENODEV; -- cgit v1.2.3