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authorChristoph Hellwig <hch@lst.de>2019-08-16 09:24:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-08-21 20:03:35 +0300
commit7b81cb6bddd2c4f2489506771070924bd0ae9902 (patch)
treee93409bd98a306bc26cc19c1c6a29f70029d42a0 /drivers/usb/host/r8a66597-hcd.c
parent0709831a50d31b3caf2237e8d7fe89e15b0d919d (diff)
downloadlinux-7b81cb6bddd2c4f2489506771070924bd0ae9902.tar.xz
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 <hch@lst.de> Link: https://lore.kernel.org/r/20190816062435.881-4-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/r8a66597-hcd.c')
-rw-r--r--drivers/usb/host/r8a66597-hcd.c6
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index 42668aeca57c..0c03ac6b0213 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -2411,12 +2411,6 @@ static int r8a66597_probe(struct platform_device *pdev)
if (usb_disabled())
return -ENODEV;
- if (pdev->dev.dma_mask) {
- ret = -EINVAL;
- dev_err(&pdev->dev, "dma not supported\n");
- goto clean_up;
- }
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENODEV;