> -----Original Message-----
> From: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> Sent: Friday, January 6, 2023 5:22 PM
> To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Thinh Nguyen
> <Thinh.Nguyen@xxxxxxxxxxxx>
> Cc: linux-usb@xxxxxxxxxxxxxxx; Jack Pham <quic_jackp@xxxxxxxxxxx>; Wesley
> Cheng <quic_wcheng@xxxxxxxxxxx>; Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> Subject: [PATCH 2/3] usb: dwc3: add dwc3_readl_notrace() function
>
> There are multiple places which will retry up to 10000 times to read a register,
It's "up to", I think at normal case, it's a small number, if a large
Iteration number is observed, probably there is something wrong should
be checked?
> when trace event enable, it is not good as all events may show same data.
>
> Add dwc3_readl_notrace() function which will not save trace event when read
> register.
Simply drop part of register read is not good, this cause the final io trace
of dwc3 is not complete, I think a full/complete foot print of io register
read/write should be kept.
Li Jun
>
> Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> ---
> drivers/usb/dwc3/core.c | 2 +-
> drivers/usb/dwc3/gadget.c | 12 ++++++------
> drivers/usb/dwc3/io.h | 10 ++++++++++
> drivers/usb/dwc3/ulpi.c | 2 +-
> 4 files changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index
> 476b636..550bb23 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -297,7 +297,7 @@ int dwc3_core_soft_reset(struct dwc3 *dwc)
> retries = 10;
>
> do {
> - reg = dwc3_readl(dwc->regs, DWC3_DCTL);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DCTL);
> if (!(reg & DWC3_DCTL_CSFTRST))
> goto done;
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index
> 7899765..f2126f24 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -97,7 +97,7 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum
> dwc3_link_state state)
> */
> if (!DWC3_VER_IS_PRIOR(DWC3, 194A)) {
> while (--retries) {
> - reg = dwc3_readl(dwc->regs, DWC3_DSTS);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DSTS);
> if (reg & DWC3_DSTS_DCNRD)
> udelay(5);
> else
> @@ -128,7 +128,7 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum
> dwc3_link_state state)
> /* wait for a change in DSTS */
> retries = 10000;
> while (--retries) {
> - reg = dwc3_readl(dwc->regs, DWC3_DSTS);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DSTS);
>
> if (DWC3_DSTS_USBLNKST(reg) == state)
> return 0;
> @@ -239,7 +239,7 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc,
> unsigned int cmd,
> dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
>
> do {
> - reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DGCMD);
> if (!(reg & DWC3_DGCMD_CMDACT)) {
> status = DWC3_DGCMD_STATUS(reg);
> if (status)
> @@ -375,7 +375,7 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep,
> unsigned int cmd,
> }
>
> do {
> - reg = dwc3_readl(dep->regs, DWC3_DEPCMD);
> + reg = dwc3_readl_notrace(dep->regs, DWC3_DEPCMD);
> if (!(reg & DWC3_DEPCMD_CMDACT)) {
> cmd_status = DWC3_DEPCMD_STATUS(reg);
>
> @@ -2324,7 +2324,7 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
> retries = 20000;
>
> while (retries--) {
> - reg = dwc3_readl(dwc->regs, DWC3_DSTS);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DSTS);
>
> /* in HS, means ON */
> if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0) @@ -2510,7
> +2510,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int
> suspend)
>
> do {
> usleep_range(1000, 2000);
> - reg = dwc3_readl(dwc->regs, DWC3_DSTS);
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_DSTS);
> reg &= DWC3_DSTS_DEVCTRLHLT;
> } while (--timeout && !(!is_on ^ !reg));
>
> diff --git a/drivers/usb/dwc3/io.h b/drivers/usb/dwc3/io.h index
> d9283f4..d24513e 100644
> --- a/drivers/usb/dwc3/io.h
> +++ b/drivers/usb/dwc3/io.h
> @@ -37,6 +37,16 @@ static inline u32 dwc3_readl(void __iomem *base, u32
> offset)
> return value;
> }
>
> +static inline u32 dwc3_readl_notrace(void __iomem *base, u32 offset) {
> + /*
> + * We requested the mem region starting from the Globals address
> + * space, see dwc3_probe in core.c.
> + * The offsets are also given starting from Globals address space.
> + */
> + return readl(base + offset);
> +}
> +
> static inline void dwc3_writel(void __iomem *base, u32 offset, u32 value)
> {
> /*
> diff --git a/drivers/usb/dwc3/ulpi.c b/drivers/usb/dwc3/ulpi.c index
> f23f4c9..7b220b0 100644
> --- a/drivers/usb/dwc3/ulpi.c
> +++ b/drivers/usb/dwc3/ulpi.c
> @@ -39,7 +39,7 @@ static int dwc3_ulpi_busyloop(struct dwc3 *dwc, u8 addr,
> bool read)
>
> while (count--) {
> ndelay(ns);
> - reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
> + reg = dwc3_readl_notrace(dwc->regs, DWC3_GUSB2PHYACC(0));
> if (reg & DWC3_GUSB2PHYACC_DONE)
> return 0;
> cpu_relax();
> --
> 2.7.4
