RE: [linux-devel] [PATCH 2/3] usb: dwc3 : Add support for USB snooping

From: Leo Li
Date: Fri Aug 11 2017 - 12:19:11 EST




> -----Original Message-----
> From: linux-devel-bounces@xxxxxxxxxxxxxxxxxxxx [mailto:linux-devel-
> bounces@xxxxxxxxxxxxxxxxxxxx] On Behalf Of yinbo.zhu@xxxxxxx
> Sent: Friday, August 11, 2017 5:00 AM
> To: linux-devel@xxxxxxxxxxxxxxxxxxxx; Yinbo Zhu <yinbo.zhu@xxxxxxx>; Rob
> Herring <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>;
> Russell King <linux@xxxxxxxxxxxxxxx>; Felipe Balbi <balbi@xxxxxxxxxx>
> Cc: open list <devicetree@xxxxxxxxxxxxxxx>; Laurent Pinchart
> <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>; Catalin Marinas
> <catalin.marinas@xxxxxxx>; open list <linux-usb@xxxxxxxxxxxxxxx>; open list
> <linux-kernel@xxxxxxxxxxxxxxx>; Doug Ledford <dledford@xxxxxxxxxx>;
> Stefano Stabellini <sstabellini@xxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Bart Van Assche
> <bart.vanassche@xxxxxxxxxxx>; moderated list <linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx>
> Subject: [linux-devel] [PATCH 2/3] usb: dwc3 : Add support for USB snooping
>
> From: Rajesh Bhagat <rajesh.bhagat@xxxxxxxxxxxxx>
>
> Add support for USB3 snooping by asserting bits in register DWC3_GSBUSCFG0
> for data and descriptor

The description doesn't fully cover the change you made below, for example allocating multiple event buffers. Please explain why you made such change.

>
> Signed-off-by: Nikhil Badola <nikhil.badola@xxxxxxxxxxxxx>
> Signed-off-by: Rajesh Bhagat <rajesh.bhagat@xxxxxxxxxxxxx>
> Signed-off-by: yinbo.zhu <yinbo.zhu@xxxxxxx>
> ---
> drivers/usb/dwc3/core.c | 71 ++++++++++++++++++++++++++++++++++++-------
> ------
> drivers/usb/dwc3/core.h | 3 +++
> drivers/usb/dwc3/host.c | 8 +++++-
> 3 files changed, 63 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index
> 02a534a..b51b0d8 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -90,6 +90,7 @@ static int dwc3_get_dr_mode(struct dwc3 *dwc)
>
> if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
> mode = USB_DR_MODE_HOST;
> +

Why are you adding a new line here?

> else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
> mode = USB_DR_MODE_PERIPHERAL;
> }
> @@ -305,14 +306,27 @@ static void dwc3_free_event_buffers(struct dwc3
> *dwc)
> */
> static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length) {
> - struct dwc3_event_buffer *evt;
> + int num;
> + int i;
> +
> + num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
> + dwc->num_event_buffers = num;
> +
> + dwc->ev_buffs = devm_kzalloc(dwc->dev, sizeof(*dwc->ev_buffs) * num,
> + GFP_KERNEL);
> + if (!dwc->ev_buffs)
> + return -ENOMEM;
>
> - evt = dwc3_alloc_one_event_buffer(dwc, length);
> - if (IS_ERR(evt)) {
> - dev_err(dwc->dev, "can't allocate event buffer\n");
> - return PTR_ERR(evt);
> + for (i = 0; i < num; i++) {
> + struct dwc3_event_buffer *evt;
> +
> + evt = dwc3_alloc_one_event_buffer(dwc, length);
> + if (IS_ERR(evt)) {
> + dev_err(dwc->dev, "can't allocate event buffer\n");
> + return PTR_ERR(evt);
> + }
> + dwc->ev_buffs[i] = evt;
> }
> - dwc->ev_buf = evt;
>
> return 0;
> }
> @@ -325,17 +339,25 @@ static int dwc3_alloc_event_buffers(struct dwc3
> *dwc, unsigned length)
> */
> static int dwc3_event_buffers_setup(struct dwc3 *dwc) {
> - struct dwc3_event_buffer *evt;
> -
> - evt = dwc->ev_buf;
> - evt->lpos = 0;
> - dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(0),
> - lower_32_bits(evt->dma));
> - dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(0),
> - upper_32_bits(evt->dma));
> - dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0),
> - DWC3_GEVNTSIZ_SIZE(evt->length));
> - dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 0);
> + struct dwc3_event_buffer *evt;
> + int n;
> +
> + for (n = 0; n < dwc->num_event_buffers; n++) {
> + evt = dwc->ev_buffs[n];
> + dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
> + evt->buf, (unsigned long long) evt->dma,
> + evt->length);
> +
> + evt->lpos = 0;
> +
> + dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
> + lower_32_bits(evt->dma));
> + dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
> + upper_32_bits(evt->dma));
> + dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
> + DWC3_GEVNTSIZ_SIZE(evt->length));
> + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
> + }
>
> return 0;
> }
> @@ -1181,6 +1203,7 @@ static void dwc3_check_params(struct dwc3 *dwc)
> static int dwc3_probe(struct platform_device *pdev) {
> struct device *dev = &pdev->dev;
> + struct device_node *node = dev->of_node;
> struct resource *res;
> struct dwc3 *dwc;
>
> @@ -1188,7 +1211,6 @@ static int dwc3_probe(struct platform_device *pdev)
>
> void __iomem *regs;
>
> - struct device_node *node = dev->of_node;
> dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
> if (!dwc)
> return -ENOMEM;
> @@ -1260,6 +1282,19 @@ static int dwc3_probe(struct platform_device *pdev)
> goto err2;
> }
>
> + /* Change burst beat and outstanding pipelined transfers requests */
> + dwc3_writel(dwc->regs, DWC3_GSBUSCFG0,
> + (dwc3_readl(dwc->regs, DWC3_GSBUSCFG0) & ~0xff) | 0xf);
> + dwc3_writel(dwc->regs, DWC3_GSBUSCFG1,
> + dwc3_readl(dwc->regs, DWC3_GSBUSCFG1) | 0xf00);
> +
> + /* Enable Snooping */
> + if (node && of_dma_is_coherent(node)) {
> + dwc3_writel(dwc->regs, DWC3_GSBUSCFG0,
> + dwc3_readl(dwc->regs, DWC3_GSBUSCFG0) | 0x22220000);
> + dev_dbg(dev, "enabled snooping for usb\n");
> + }
> +
> ret = dwc3_get_dr_mode(dwc);
> if (ret)
> goto err3;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index
> b83388f..e075665 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -29,6 +29,7 @@
> #include <linux/debugfs.h>
> #include <linux/wait.h>
> #include <linux/workqueue.h>
> +#include <linux/of_address.h>
>
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> @@ -913,6 +914,7 @@ struct dwc3 {
> struct platform_device *xhci;
> struct resource
> xhci_resources[DWC3_XHCI_RESOURCES_NUM];
>
> + struct dwc3_event_buffer **ev_buffs;
> struct dwc3_event_buffer *ev_buf;
> struct dwc3_ep *eps[DWC3_ENDPOINTS_NUM];
>
> @@ -946,6 +948,7 @@ struct dwc3 {
> u32 incrx_type[2];
> u32 irq_gadget;
> u32 nr_scratch;
> + u32 num_event_buffers;
> u32 u1u2;
> u32 maximum_speed;
>
> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c index
> 3e85616..0f2b86c 100644
> --- a/drivers/usb/dwc3/host.c
> +++ b/drivers/usb/dwc3/host.c
> @@ -93,8 +93,14 @@ int dwc3_host_init(struct dwc3 *dwc)
> dma_set_coherent_mask(&xhci->dev, dwc->dev-
> >coherent_dma_mask);
>
> xhci->dev.parent = dwc->dev;
> -
> xhci->dev.dma_mask = dwc->dev->dma_mask;
> + xhci->dev.dma_parms = dwc->dev->dma_parms;
> +
> + /* set DMA operations */
> + if (dwc->dev->of_node && of_dma_is_coherent(dwc->dev->of_node)) {
> + xhci->dev.archdata.dma_ops = dwc->dev->archdata.dma_ops;
> + dev_dbg(dwc->dev, "set dma_ops for usb\n");
> + }
>
> dwc->xhci = xhci;
>
> --
> 2.1.0.27.g96db324
>
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