Re: [PATCH v5 3/3] USB3/DWC3: Enable undefined length INCR burst type
From: Rob Herring
Date: Wed Mar 07 2018 - 20:35:14 EST
On Tue, Mar 06, 2018 at 04:59:11PM +0800, Ran Wang wrote:
> Enable the undefined length INCR burst type and set INCRx.
> Different platform may has the different burst size type.
> In order to get best performance, we need to tune the burst size to
> one special value, instead of the default value.
>
> Signed-off-by: Changming Huang <jerry.huang@xxxxxxx>
> Signed-off-by: Rajesh Bhagat <rajesh.bhagat@xxxxxxx>
> Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
> ---
> Changes in v5:
> - no change
> Changes in v4:
> - Modify the codes according to the definition of this property.
> Changes in v3:
> - add new property for INCR burst in usb node to reset GSBUSCFG0.
> Changes in v2:
> - split patch
> - create one new function to handle soc bus configuration register.
>
> drivers/usb/dwc3/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/dwc3/core.h | 7 ++++
> 2 files changed, 90 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index f1d838a..8ea2bc8 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -741,6 +741,87 @@ static void dwc3_core_setup_global_control(struct dwc3 *dwc)
> static int dwc3_core_get_phy(struct dwc3 *dwc);
> static int dwc3_core_ulpi_init(struct dwc3 *dwc);
>
> +/* set global soc bus configuration registers */
> +static void dwc3_set_soc_bus_cfg(struct dwc3 *dwc)
> +{
> + struct device *dev = dwc->dev;
> + u32 *vals;
> + u32 cfg;
> + int ntype;
> + int ret;
> + int i;
> +
> + cfg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
> +
> + /*
> + * Handle property "snps,incr-burst-type-adjustment".
> + * Get the number of value from this property:
> + * result <= 0, means this property is not supported.
> + * result = 1, means INCRx burst mode supported.
> + * result > 1, means undefined length burst mode supported.
> + */
> + ntype = device_property_read_u32_array(dev,
> + "snps,incr-burst-type-adjustment", NULL, 0);
Can't you just do:
if (ntype <= 0)
return;
> + if (ntype > 0) {
And then save a level of indentation.
> + vals = kcalloc(ntype, sizeof(u32), GFP_KERNEL);
> + if (!vals) {
> + dev_err(dev, "Error to get memory\n");
> + return;
> + }
> + /* Get INCR burst type, and parse it */
> + ret = device_property_read_u32_array(dev,
> + "snps,incr-burst-type-adjustment", vals, ntype);
> + if (ret) {
> + dev_err(dev, "Error to get property\n");
> + return;
> + }
> + *(dwc->incrx_type + 1) = vals[0];
> + if (ntype > 1) {
> + *dwc->incrx_type = 1;
> + for (i = 1; i < ntype; i++) {
> + if (vals[i] > *(dwc->incrx_type + 1))
> + *(dwc->incrx_type + 1) = vals[i];
> + }
> + } else
> + *dwc->incrx_type = 0;
This code is hard to follow. Why do you have an array to store a boolean
(INCR burst enable) and the burst size. 2 elements with more descriptive
names would be better.
> +
> + /* Enable Undefined Length INCR Burst and Enable INCRx Burst */
> + cfg &= ~DWC3_GSBUSCFG0_INCRBRST_MASK;
> + if (*dwc->incrx_type)
> + cfg |= DWC3_GSBUSCFG0_INCRBRSTENA;
> + switch (*(dwc->incrx_type + 1)) {
> + case 256:
> + cfg |= DWC3_GSBUSCFG0_INCR256BRSTENA;
> + break;
> + case 128:
> + cfg |= DWC3_GSBUSCFG0_INCR128BRSTENA;
> + break;
> + case 64:
> + cfg |= DWC3_GSBUSCFG0_INCR64BRSTENA;
> + break;
> + case 32:
> + cfg |= DWC3_GSBUSCFG0_INCR32BRSTENA;
> + break;
> + case 16:
> + cfg |= DWC3_GSBUSCFG0_INCR16BRSTENA;
> + break;
> + case 8:
> + cfg |= DWC3_GSBUSCFG0_INCR8BRSTENA;
> + break;
> + case 4:
> + cfg |= DWC3_GSBUSCFG0_INCR4BRSTENA;
> + break;
> + case 1:
> + break;
> + default:
> + dev_err(dev, "Invalid property\n");
> + break;
> + }
> + }
> +
> + dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, cfg);
> +}
> +
> /**
> * dwc3_core_init - Low-level initialization of DWC3 Core
> * @dwc: Pointer to our controller context structure
> @@ -803,6 +884,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
> /* Adjust Frame Length */
> dwc3_frame_length_adjustment(dwc);
>
> + dwc3_set_soc_bus_cfg(dwc);
> +
> usb_phy_set_suspend(dwc->usb2_phy, 0);
> usb_phy_set_suspend(dwc->usb3_phy, 0);
> ret = phy_power_on(dwc->usb2_generic_phy);
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 8f97f61..565d7ec 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -806,6 +806,7 @@ struct dwc3_scratchpad_array {
> * @regs: base address for our registers
> * @regs_size: address space size
> * @fladj: frame length adjustment
> + * @incrx_type: INCR burst type adjustment
> * @irq_gadget: peripheral controller's IRQ number
> * @nr_scratch: number of scratch buffers
> * @u1u2: only used on revisions <1.83a for workaround
> @@ -939,6 +940,12 @@ struct dwc3 {
> enum usb_phy_interface hsphy_mode;
>
> u32 fladj;
> + /*
> + * For INCR burst type.
> + * First field: for undefined length INCR burst type enable.
> + * Second field: for INCRx burst type enable
> + */
> + u32 incrx_type[2];
> u32 irq_gadget;
> u32 nr_scratch;
> u32 u1u2;
> --
> 1.7.1
>
>
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