6.6-stable review patch. If anyone has any objections, please let me know.
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From: Jos Wang joswang@lenovo.com
commit fc1d1a712b517bbcb383b1f1f7ef478e7d0579f2 upstream.
This is a workaround for STAR 4846132, which only affects DWC_usb31 version2.00a operating in host mode.
There is a problem in DWC_usb31 version 2.00a operating in host mode that would cause a CSR read timeout When CSR read coincides with RAM Clock Gating Entry. By disable Clock Gating, sacrificing power consumption for normal operation.
Cc: stable stable@kernel.org # 5.10.x: 1e43c86d: usb: dwc3: core: Add DWC31 version 2.00a controller Signed-off-by: Jos Wang joswang@lenovo.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/20240619114529.3441-1-joswang1221@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/core.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
--- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -865,12 +865,16 @@ static bool dwc3_core_is_valid(struct dw
static void dwc3_core_setup_global_control(struct dwc3 *dwc) { + unsigned int power_opt; + unsigned int hw_mode; u32 reg;
reg = dwc3_readl(dwc->regs, DWC3_GCTL); reg &= ~DWC3_GCTL_SCALEDOWN_MASK; + hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0); + power_opt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1);
- switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) { + switch (power_opt) { case DWC3_GHWPARAMS1_EN_PWROPT_CLK: /** * WORKAROUND: DWC3 revisions between 2.10a and 2.50a have an @@ -903,6 +907,20 @@ static void dwc3_core_setup_global_contr break; }
+ /* + * This is a workaround for STAR#4846132, which only affects + * DWC_usb31 version2.00a operating in host mode. + * + * There is a problem in DWC_usb31 version 2.00a operating + * in host mode that would cause a CSR read timeout When CSR + * read coincides with RAM Clock Gating Entry. By disable + * Clock Gating, sacrificing power consumption for normal + * operation. + */ + if (power_opt != DWC3_GHWPARAMS1_EN_PWROPT_NO && + hw_mode != DWC3_GHWPARAMS0_MODE_GADGET && DWC3_VER_IS(DWC31, 200A)) + reg |= DWC3_GCTL_DSBLCLKGTNG; + /* check if current dwc3 is on simulation board */ if (dwc->hwparams.hwparams6 & DWC3_GHWPARAMS6_EN_FPGA) { dev_info(dwc->dev, "Running with FPGA optimizations\n");