From 6d86c1b463f7c26fd16f06d6884fb1d7fdb88ca9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Draszik?= Date: Mon, 9 Dec 2024 11:49:53 +0000 Subject: [PATCH] usb: dwc3: gadget: fix writing NYET threshold MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 01ea6bf5cb58b20cc1bd159f0cf74a76cf04bb69 upstream. Before writing a new value to the register, the old value needs to be masked out for the new value to be programmed as intended, because at least in some cases the reset value of that field is 0xf (max value). At the moment, the dwc3 core initialises the threshold to the maximum value (0xf), with the option to override it via a DT. No upstream DTs seem to override it, therefore this commit doesn't change behaviour for any upstream platform. Nevertheless, the code should be fixed to have the desired outcome. Do so. Fixes: 80caf7d21adc ("usb: dwc3: add lpm erratum support") Cc: stable@vger.kernel.org # 5.10+ (needs adjustment for 5.4) Signed-off-by: André Draszik Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20241209-dwc3-nyet-fix-v2-1-02755683345b@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/core.h | 1 + drivers/usb/dwc3/gadget.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 0b9ba338b265..0e91a227507f 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -464,6 +464,7 @@ #define DWC3_DCTL_TRGTULST_SS_INACT (DWC3_DCTL_TRGTULST(6)) /* These apply for core versions 1.94a and later */ +#define DWC3_DCTL_NYET_THRES_MASK (0xf << 20) #define DWC3_DCTL_NYET_THRES(n) (((n) & 0xf) << 20) #define DWC3_DCTL_KEEP_CONNECT BIT(19) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 56744b11e67c..a5d75d7d0a87 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4208,8 +4208,10 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc) WARN_ONCE(DWC3_VER_IS_PRIOR(DWC3, 240A) && dwc->has_lpm_erratum, "LPM Erratum not available on dwc3 revisions < 2.40a\n"); - if (dwc->has_lpm_erratum && !DWC3_VER_IS_PRIOR(DWC3, 240A)) + if (dwc->has_lpm_erratum && !DWC3_VER_IS_PRIOR(DWC3, 240A)) { + reg &= ~DWC3_DCTL_NYET_THRES_MASK; reg |= DWC3_DCTL_NYET_THRES(dwc->lpm_nyet_threshold); + } dwc3_gadget_dctl_write_safe(dwc, reg); } else {