From patchwork Tue Mar 10 10:09:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Delaunay X-Patchwork-Id: 243475 List-Id: U-Boot discussion From: patrick.delaunay at st.com (Patrick Delaunay) Date: Tue, 10 Mar 2020 11:09:11 +0100 Subject: [PATCH v6 4/5] usb: host: dwc2: force reset assert In-Reply-To: <20200310100912.28129-1-patrick.delaunay@st.com> References: <20200310100912.28129-1-patrick.delaunay@st.com> Message-ID: <20200310100912.28129-5-patrick.delaunay@st.com> Assert reset before deassert in dwc2_reset; this patch solve issues when the DWC2 registers are already initialized with value incompatible with host mode. Force a hardware reset of the IP reset all the DWC2 registers at default value, the host driver start with a clean state (Core Soft reset doen in dwc_otg_core_reset is not enought to reset all register). The error can occurs in U-Boot when DWC2 device gadget driver force device mode (called by ums or dfu command, before to execute the usb start command). Signed-off-by: Patrick Delaunay Reviewed-by: Simon Goldschmidt --- Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: - add clk_disable_bulk in dwc2_usb_remove drivers/usb/host/dwc2.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c index b1b79d0a18..640ae3e730 100644 --- a/drivers/usb/host/dwc2.c +++ b/drivers/usb/host/dwc2.c @@ -1151,6 +1151,8 @@ static int dwc2_reset(struct udevice *dev) return ret; } + /* force reset to clear all IP register */ + reset_assert_bulk(&priv->resets); ret = reset_deassert_bulk(&priv->resets); if (ret) { reset_release_bulk(&priv->resets);