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authorWayne Chang <waynec@nvidia.com>2025-04-18 16:12:28 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-05-18 08:24:55 +0200
commit43ae91f561de47465a6a10b8633dbf222f2706d5 (patch)
treebb79d7ff427d8c42301b5c0eefabf868e56cd753
parent75f23e49add86a2ede5214dd03f3e3976197a880 (diff)
usb: gadget: tegra-xudc: ACK ST_RC after clearing CTRL_RUN
commit 59820fde001500c167342257650541280c622b73 upstream. We identified a bug where the ST_RC bit in the status register was not being acknowledged after clearing the CTRL_RUN bit in the control register. This could lead to unexpected behavior in the USB gadget drivers. This patch resolves the issue by adding the necessary code to explicitly acknowledge ST_RC after clearing CTRL_RUN based on the programming sequence, ensuring proper state transition. Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller") Cc: stable <stable@kernel.org> Signed-off-by: Wayne Chang <waynec@nvidia.com> Link: https://lore.kernel.org/r/20250418081228.1194779-1-waynec@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/udc/tegra-xudc.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
index 7aa46d426f31..9bb54da8a6ae 100644
--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -1749,6 +1749,10 @@ static int __tegra_xudc_ep_disable(struct tegra_xudc_ep *ep)
val = xudc_readl(xudc, CTRL);
val &= ~CTRL_RUN;
xudc_writel(xudc, val, CTRL);
+
+ val = xudc_readl(xudc, ST);
+ if (val & ST_RC)
+ xudc_writel(xudc, ST_RC, ST);
}
dev_info(xudc->dev, "ep %u disabled\n", ep->index);