On 4/14/14 4:11 PM, dinguyen@xxxxxxxxxx wrote:
> From: Dinh Nguyen <dinguyen@xxxxxxxxxx>
>
> The dwc2 IP on the SOCFPGA cannot use the default HW configured
> FIFO sizes. The total FIFO depth as read from GHWCFG3 reports 0x1f80 or 8064
> 32-bit words. But the GRXFSIZ, GNPTXFSIZ, and HPTXFSIZ register defaults
> to 0x2000 or 8192 32-bit words. So the driver cannot just use the fifo sizes
> as read from those registers.
>
> For platforms that face the same issue, this commits sets the RX, periodic TX,
> and non-periodic TX fifo size to those that are recommended v2.93a spec for
> the DWC2 IP. Implements Method #2 from the Synopsys v2.93a spec for the DWC2.
>
> Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
> Acked-by: Paul Zimmerman <paulz@xxxxxxxxxxxx>
> Reviewed-by: Felipe Balbi <balbi@xxxxxx>
> ---
> v5:
> - Fix build error around dev_err()
>
> v4:
> - Fix comment style errors
> - Use comment suggestion from Felipe to clearly commmunicate invalid fifo sizes
> - Removed useless comment
>
> v3:
> - Address comments from Felipe
> - Used Method 2 as recommended by Synopsys to high-bandwidth endpoints.
>
> v2:
> - Fix coding style with braces around both if() branches
> ---
> drivers/usb/dwc2/core.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index 1d12988..27d2c9b 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -507,6 +507,72 @@ void dwc2_disable_host_interrupts(struct dwc2_hsotg *hsotg)
> writel(intmsk, hsotg->regs + GINTMSK);
> }
>
> +/*
> + * dwc2_calculate_dynamic_fifo() - Calculates the default fifo size
> + * For system that have a total fifo depth that is smaller than the default
> + * RX + TX fifo size.
> + *
> + * @hsotg: Programming view of DWC_otg controller
> + */
> +static void dwc2_calculate_dynamic_fifo(struct dwc2_hsotg *hsotg)
> +{
> + struct dwc2_core_params *params = hsotg->core_params;
> + struct dwc2_hw_params *hw = &hsotg->hw_params;
> + u32 rxfsiz, nptxfsiz, ptxfsiz, total_fifo_size;
> +
> + total_fifo_size = hw->total_fifo_size;
> + rxfsiz = params->host_rx_fifo_size;
> + nptxfsiz = params->host_nperio_tx_fifo_size;
> + ptxfsiz = params->host_perio_tx_fifo_size;
> +
> + /*
> + * Will use Method 2 defined in the DWC2 spec: minimum FIFO depth
> + * allocation with support for high bandwidth endpoints. Synopsys
> + * defines MPS(Max Packet size) for a periodic EP=1024, and for
> + * non-periodic as 512.
> + */
> + if (total_fifo_size < (rxfsiz + nptxfsiz + ptxfsiz)) {
> + /*
> + * For Buffer DMA mode/Scatter Gather DMA mode
> + * 2 * ((Largest Packet size / 4) + 1 + 1) + n
> + * with n = number of host channel.
> + * 2 * ((1024/4) + 2) = 516
> + */
> + rxfsiz = 516 + hw->host_channels;
> +
> + /*
> + * min non-periodic tx fifo depth
> + * 2 * (largest non-periodic USB packet used / 4)
> + * 2 * (512/4) = 256
> + */
> + nptxfsiz = 256;
> +
> + /*
> + * min periodic tx fifo depth
> + * (largest packet size*MC)/4
> + * (1024 * 3)/4 = 768
> + */
> + ptxfsiz = 768;
> +
> + params->host_rx_fifo_size = rxfsiz;
> + params->host_nperio_tx_fifo_size = nptxfsiz;
> + params->host_perio_tx_fifo_size = ptxfsiz;
> + }
> +
> + /*
> + * If the summation of RX, NPTX and PTX fifo sizes is still
> + * bigger than the total_fifo_size, then we have a problem.
> + *
> + * We won't be able to allocate as many endpoints. Right now,
> + * we're just printing an error message, but ideally this FIFO
> + * allocation algorithm would be improved in the future.
> + *
> + * FIXME improve this FIFO allocation algorithm.
> + */
> + if (unlikely(total_fifo_size < (rxfsiz + nptxfsiz + ptxfsiz)))
> + dev_err(hsotg->dev, "invalid fifo sizes\n");
> +}
> +
> static void dwc2_config_fifos(struct dwc2_hsotg *hsotg)
> {
> struct dwc2_core_params *params = hsotg->core_params;
> @@ -515,6 +581,8 @@ static void dwc2_config_fifos(struct dwc2_hsotg *hsotg)
> if (!params->enable_dynamic_fifo)
> return;
>
> + dwc2_calculate_dynamic_fifo(hsotg);
> +
> /* Rx FIFO */
> grxfsiz = readl(hsotg->regs + GRXFSIZ);
> dev_dbg(hsotg->dev, "initial grxfsiz=%08x\n", grxfsiz);
Hi Greg,
If you're ok with this patch, can you please apply this to usb-next?
Thanks,
Dinh
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