[PATCH 3/6] 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 --- drivers/staging/octeon-usb/octeon-hcd.c | 2 +- drivers/usb/core/hcd.c | 1 - drivers/usb/dwc2/hcd.c | 6 +++--- drivers/usb/host/ehci-grlib.c | 2 +- drivers/usb/host/ehci-hcd.c | 2 +- drivers/usb/host/ehci-pmcmsp.c | 2 +- drivers/usb/host/ehci-ppc-of.c | 2 +- drivers/usb/host/ehci-ps3.c | 2 +- drivers/usb/host/ehci-sh.c | 2 +- drivers/usb/host/ehci-xilinx-of.c | 2 +- drivers/usb/host/fhci-hcd.c | 2 +- drivers/usb/host/fotg210-hcd.c | 2 +- drivers/usb/host/imx21-hcd.c| 2 +- drivers/usb/host/isp116x-hcd.c | 6 -- drivers/usb/host/isp1362-hcd.c | 5 - drivers/usb/host/ohci-hcd.c | 2 +- drivers/usb/host/ohci-ppc-of.c | 2 +- drivers/usb/host/ohci-ps3.c | 2 +- drivers/usb/host/ohci-sa.c | 2 +- drivers/usb/host/ohci-sm501.c | 2 +- drivers/usb/host/ohci-tmio.c| 2 +- drivers/usb/host/oxu210hp-hcd.c | 3 --- drivers/usb/host/r8a66597-hcd.c | 6 -- drivers/usb/host/sl811-hcd.c| 6 -- drivers/usb/host/u132-hcd.c | 2 -- drivers/usb/host/uhci-grlib.c | 2 +- drivers/usb/host/uhci-pci.c | 2 +- drivers/usb/host/uhci-platform.c| 2 +- drivers/usb/host/xhci.c | 2 +- drivers/usb/isp1760/isp1760-core.c | 3 --- drivers/usb/isp1760/isp1760-if.c| 1 - drivers/usb/musb/musb_host.c| 2 +- drivers/usb/renesas_usbhs/mod_host.c| 2 +- include/linux/usb.h | 1 - include/linux/usb/hcd.h | 7 +-- 35 files changed, 31 insertions(+), 62 deletions(-) diff --git a/drivers/staging/octeon-usb/octeon-hcd.c b/drivers/staging/octeon-usb/octeon-hcd.c index cd2b777073c4..a5321cc692c5 100644 --- a/drivers/staging/octeon-usb/octeon-hcd.c +++ b/drivers/staging/octeon-usb/octeon-hcd.c @@ -3512,7 +3512,7 @@ static const struct hc_driver octeon_hc_driver = { .product_desc = "Octeon Host Controller", .hcd_priv_size = sizeof(struct octeon_hcd), .irq= octeon_usb_irq, - .flags = HCD_MEMORY | HCD_USB2, + .flags = HCD_MEMORY | HCD_DMA | HCD_USB2, .start = octeon_usb_start, .stop = octeon_usb_stop, .urb_enqueue= octeon_usb_urb_enqueue, diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 8592c0344fe8..add2af4af766 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2454,7 +2454,6 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, hcd->self.controller = dev; hcd->self.sysdev = sysdev; hcd->self.bus_name = bus_name; - hcd->self.uses_dma = (sysdev->dma_mask != NULL); timer_setup(&hcd->rh_timer, rh_timer_func, 0); #ifdef CONFIG_PM diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 111787a137ee..81afe553aa66 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -5062,13 +5062,13 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg) dwc2_hc_driver.reset_device = dwc2_reset_device; } + if (hsotg->params.host_dma) + dwc2_hc_driver.flags |= HCD_DMA; + hcd = usb_create_hcd(&dwc2_hc_driver, hsotg->dev, dev_name(hsotg->dev)); if (!hcd) goto error1; - if (!hsotg->params.host_dma) - hcd->self.uses_dma = 0; - hcd->has_tt = 1; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); diff --git a/drivers/usb/host/ehci-grlib.c b/drivers/usb/host/ehci-grlib.c index 656b8c08efc8..a2c3b4ec8a8b 100644 --- a/drivers/usb/host/ehci-grlib.c +++ b/drivers/usb/host/ehci-grlib.c @@ -30,7 +30,7 @@ static const struct hc_driver ehci_grlib_hc_driver = { * generic hardware linkage */ .irq= ehci_irq, - .flags = HCD_MEMORY | HCD_USB2 | HCD_BH, + .flags = HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH, /* * basic lifecycle operations diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 9da7e22848c9..cf2b7ae93b7e 100644 --- a/drivers/usb/host
Re: [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities
> diff --git a/drivers/usb/host/ehci-ppc-of.c b/drivers/usb/host/ehci-ppc-of.c > index 576f7d79ad4e..9d17e0695e35 100644 > --- a/drivers/usb/host/ehci-ppc-of.c > +++ b/drivers/usb/host/ehci-ppc-of.c > @@ -31,7 +31,7 @@ static const struct hc_driver ehci_ppc_of_hc_driver = { >* generic hardware linkage >*/ > .irq= ehci_irq, > - .flags = HCD_MEMORY | HCD_USB2 | HCD_BH, > + .flags = HCD_MEMORY | HC_DMA | HCD_USB2 | HCD_BH, FYI, the kbuild bot found a little typo here, so even for the unlikely case that the series is otherwise perfect I'll have to resend it at least once.
[PATCH 3/6] 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 --- drivers/staging/octeon-usb/octeon-hcd.c | 2 +- drivers/usb/core/hcd.c | 1 - drivers/usb/dwc2/hcd.c | 6 +++--- drivers/usb/host/ehci-grlib.c | 2 +- drivers/usb/host/ehci-hcd.c | 2 +- drivers/usb/host/ehci-pmcmsp.c | 2 +- drivers/usb/host/ehci-ppc-of.c | 2 +- drivers/usb/host/ehci-ps3.c | 2 +- drivers/usb/host/ehci-sh.c | 2 +- drivers/usb/host/ehci-xilinx-of.c | 2 +- drivers/usb/host/fhci-hcd.c | 2 +- drivers/usb/host/fotg210-hcd.c | 2 +- drivers/usb/host/imx21-hcd.c| 2 +- drivers/usb/host/isp116x-hcd.c | 6 -- drivers/usb/host/isp1362-hcd.c | 5 - drivers/usb/host/ohci-hcd.c | 2 +- drivers/usb/host/ohci-ppc-of.c | 2 +- drivers/usb/host/ohci-ps3.c | 2 +- drivers/usb/host/ohci-sa.c | 2 +- drivers/usb/host/ohci-sm501.c | 2 +- drivers/usb/host/ohci-tmio.c| 2 +- drivers/usb/host/oxu210hp-hcd.c | 3 --- drivers/usb/host/r8a66597-hcd.c | 6 -- drivers/usb/host/sl811-hcd.c| 6 -- drivers/usb/host/u132-hcd.c | 2 -- drivers/usb/host/uhci-grlib.c | 2 +- drivers/usb/host/uhci-pci.c | 2 +- drivers/usb/host/uhci-platform.c| 2 +- drivers/usb/host/xhci.c | 2 +- drivers/usb/isp1760/isp1760-core.c | 3 --- drivers/usb/isp1760/isp1760-if.c| 1 - drivers/usb/musb/musb_host.c| 2 +- drivers/usb/renesas_usbhs/mod_host.c| 2 +- include/linux/usb.h | 1 - include/linux/usb/hcd.h | 7 +-- 35 files changed, 31 insertions(+), 62 deletions(-) diff --git a/drivers/staging/octeon-usb/octeon-hcd.c b/drivers/staging/octeon-usb/octeon-hcd.c index cd2b777073c4..a5321cc692c5 100644 --- a/drivers/staging/octeon-usb/octeon-hcd.c +++ b/drivers/staging/octeon-usb/octeon-hcd.c @@ -3512,7 +3512,7 @@ static const struct hc_driver octeon_hc_driver = { .product_desc = "Octeon Host Controller", .hcd_priv_size = sizeof(struct octeon_hcd), .irq= octeon_usb_irq, - .flags = HCD_MEMORY | HCD_USB2, + .flags = HCD_MEMORY | HCD_DMA | HCD_USB2, .start = octeon_usb_start, .stop = octeon_usb_stop, .urb_enqueue= octeon_usb_urb_enqueue, diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 8592c0344fe8..add2af4af766 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2454,7 +2454,6 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, hcd->self.controller = dev; hcd->self.sysdev = sysdev; hcd->self.bus_name = bus_name; - hcd->self.uses_dma = (sysdev->dma_mask != NULL); timer_setup(&hcd->rh_timer, rh_timer_func, 0); #ifdef CONFIG_PM diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 111787a137ee..81afe553aa66 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -5062,13 +5062,13 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg) dwc2_hc_driver.reset_device = dwc2_reset_device; } + if (hsotg->params.host_dma) + dwc2_hc_driver.flags |= HCD_DMA; + hcd = usb_create_hcd(&dwc2_hc_driver, hsotg->dev, dev_name(hsotg->dev)); if (!hcd) goto error1; - if (!hsotg->params.host_dma) - hcd->self.uses_dma = 0; - hcd->has_tt = 1; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); diff --git a/drivers/usb/host/ehci-grlib.c b/drivers/usb/host/ehci-grlib.c index 656b8c08efc8..a2c3b4ec8a8b 100644 --- a/drivers/usb/host/ehci-grlib.c +++ b/drivers/usb/host/ehci-grlib.c @@ -30,7 +30,7 @@ static const struct hc_driver ehci_grlib_hc_driver = { * generic hardware linkage */ .irq= ehci_irq, - .flags = HCD_MEMORY | HCD_USB2 | HCD_BH, + .flags = HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH, /* * basic lifecycle operations diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 9da7e22848c9..cf2b7ae93b7e 100644 --- a/drivers/usb/host