[PATCH 3/3] usb: dwc3: gadget: Skip reading GEVNTSIZn
From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Date: 2021-11-30 02:53:25
Subsystem:
designware usb3 drd ip driver, the rest, usb subsystem · Maintainers:
Thinh Nguyen, Linus Torvalds, Greg Kroah-Hartman
The driver knows what it needs to set for GEVNTSIZn, and the controller doesn't modify this register unless there's a hard reset. To save a few microseconds of register read in read-modify-write operation, simply do register write with the expected values. This can improve performance when there are many interrupts generated, which the driver needs to check and handle. Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> --- drivers/usb/dwc3/gadget.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index f66baaef8a40..c0c89374716b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c@@ -4082,7 +4082,6 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) struct dwc3 *dwc = evt->dwc; irqreturn_t ret = IRQ_NONE; int left; - u32 reg; left = evt->count;
@@ -4114,9 +4113,8 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) ret = IRQ_HANDLED; /* Unmask interrupt */ - reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0)); - reg &= ~DWC3_GEVNTSIZ_INTMASK; - dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg); + dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), + DWC3_GEVNTSIZ_SIZE(evt->length)); if (dwc->imod_interval) { dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
@@ -4145,7 +4143,6 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) struct dwc3 *dwc = evt->dwc; u32 amount; u32 count; - u32 reg; if (pm_runtime_suspended(dwc->dev)) { pm_runtime_get(dwc->dev);
@@ -4172,9 +4169,8 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) evt->flags |= DWC3_EVENT_PENDING; /* Mask interrupt */ - reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0)); - reg |= DWC3_GEVNTSIZ_INTMASK; - dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg); + dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), + DWC3_GEVNTSIZ_INTMASK | DWC3_GEVNTSIZ_SIZE(evt->length)); amount = min(count, evt->length - evt->lpos); memcpy(evt->cache + evt->lpos, evt->buf + evt->lpos, amount);
--
2.28.0