The existing implementation of the TxFIFO resizing logic only supports scenarios where more than one port RAM is used. However, there is a need to resize the TxFIFO in USB2.0-only mode where only a single port RAM is available. This commit introduces the necessary changes to support TxFIFO resizing in such scenarios. Cc: stable@xxxxxxxxxxxxxxx # 6.12.x: fad16c82: usb: dwc3: gadget: Refine the logic for resizing Tx FIFOs Signed-off-by: Selvarasu Ganesan <selvarasu.g@xxxxxxxxxxx> --- Changes in v2: - Removed the code change that limits the number of FIFOs for bulk EP, as plan to address this issue in a separate patch. - Renamed the variable spram_type to is_single_port_ram for better understanding. - Link to v1: https://lore.kernel.org/lkml/20241107104040.502-1-selvarasu.g@xxxxxxxxxxx/ --- drivers/usb/dwc3/core.h | 4 +++ drivers/usb/dwc3/gadget.c | 54 +++++++++++++++++++++++++++++++++------ 2 files changed, 50 insertions(+), 8 deletions(-) diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index eaa55c0cf62f..8306b39e5c64 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -915,6 +915,7 @@ struct dwc3_hwparams { #define DWC3_MODE(n) ((n) & 0x7) /* HWPARAMS1 */ +#define DWC3_SPRAM_TYPE(n) (((n) >> 23) & 1) #define DWC3_NUM_INT(n) (((n) & (0x3f << 15)) >> 15) /* HWPARAMS3 */ @@ -925,6 +926,9 @@ struct dwc3_hwparams { #define DWC3_NUM_IN_EPS(p) (((p)->hwparams3 & \ (DWC3_NUM_IN_EPS_MASK)) >> 18) +/* HWPARAMS6 */ +#define DWC3_RAM0_DEPTH(n) (((n) & (0xffff0000)) >> 16) + /* HWPARAMS7 */ #define DWC3_RAM1_DEPTH(n) ((n) & 0xffff) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 2fed2aa01407..4f2e063c9091 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -687,6 +687,44 @@ static int dwc3_gadget_calc_tx_fifo_size(struct dwc3 *dwc, int mult) return fifo_size; } +/** + * dwc3_gadget_calc_ram_depth - calculates the ram depth for txfifo + * @dwc: pointer to the DWC3 context + */ +static int dwc3_gadget_calc_ram_depth(struct dwc3 *dwc) +{ + int ram_depth; + int fifo_0_start; + bool is_single_port_ram; + int tmp; + + /* Check supporting RAM type by HW */ + is_single_port_ram = DWC3_SPRAM_TYPE(dwc->hwparams.hwparams1); + + /* + * If a single port RAM is utilized, then allocate TxFIFOs from + * RAM0. otherwise, allocate them from RAM1. + */ + ram_depth = is_single_port_ram ? DWC3_RAM0_DEPTH(dwc->hwparams.hwparams6) : + DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7); + + + /* + * In a single port RAM configuration, the available RAM is shared + * between the RX and TX FIFOs. This means that the txfifo can begin + * at a non-zero address. + */ + if (is_single_port_ram) { + /* Check if TXFIFOs start at non-zero addr */ + tmp = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(0)); + fifo_0_start = DWC3_GTXFIFOSIZ_TXFSTADDR(tmp); + + ram_depth -= (fifo_0_start >> 16); + } + + return ram_depth; +} + /** * dwc3_gadget_clear_tx_fifos - Clears txfifo allocation * @dwc: pointer to the DWC3 context @@ -753,7 +791,7 @@ static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep) { struct dwc3 *dwc = dep->dwc; int fifo_0_start; - int ram1_depth; + int ram_depth; int fifo_size; int min_depth; int num_in_ep; @@ -773,7 +811,7 @@ static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep) if (dep->flags & DWC3_EP_TXFIFO_RESIZED) return 0; - ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7); + ram_depth = dwc3_gadget_calc_ram_depth(dwc); switch (dwc->gadget->speed) { case USB_SPEED_SUPER_PLUS: @@ -809,7 +847,7 @@ static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep) /* Reserve at least one FIFO for the number of IN EPs */ min_depth = num_in_ep * (fifo + 1); - remaining = ram1_depth - min_depth - dwc->last_fifo_depth; + remaining = ram_depth - min_depth - dwc->last_fifo_depth; remaining = max_t(int, 0, remaining); /* * We've already reserved 1 FIFO per EP, so check what we can fit in @@ -835,9 +873,9 @@ static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep) dwc->last_fifo_depth += DWC31_GTXFIFOSIZ_TXFDEP(fifo_size); /* Check fifo size allocation doesn't exceed available RAM size. */ - if (dwc->last_fifo_depth >= ram1_depth) { + if (dwc->last_fifo_depth >= ram_depth) { dev_err(dwc->dev, "Fifosize(%d) > RAM size(%d) %s depth:%d\n", - dwc->last_fifo_depth, ram1_depth, + dwc->last_fifo_depth, ram_depth, dep->endpoint.name, fifo_size); if (DWC3_IP_IS(DWC3)) fifo_size = DWC3_GTXFIFOSIZ_TXFDEP(fifo_size); @@ -3090,7 +3128,7 @@ static int dwc3_gadget_check_config(struct usb_gadget *g) struct dwc3 *dwc = gadget_to_dwc(g); struct usb_ep *ep; int fifo_size = 0; - int ram1_depth; + int ram_depth; int ep_num = 0; if (!dwc->do_fifo_resize) @@ -3113,8 +3151,8 @@ static int dwc3_gadget_check_config(struct usb_gadget *g) fifo_size += dwc->max_cfg_eps; /* Check if we can fit a single fifo per endpoint */ - ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7); - if (fifo_size > ram1_depth) + ram_depth = dwc3_gadget_calc_ram_depth(dwc); + if (fifo_size > ram_depth) return -ENOMEM; return 0; -- 2.17.1
