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authorAndrey Konovalov <andreyknvl@gmail.com>2023-08-28 17:43:04 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-10-02 16:43:05 +0200
commitfc85c59b85d111f51b58ecf08485fa74ac5471cd (patch)
treef06bea30572db9b724d536e01f37ef87e35ee831
parentcf9f7a6ee7b1f53f9ae13da55585b7d16aee2460 (diff)
usb: gadgetfs: return USB_GADGET_DELAYED_STATUS from setup()
Return USB_GADGET_DELAYED_STATUS from the setup() callback for 0-length transfers as a workaround to stop some UDC drivers (e.g. dwc3) from automatically proceeding with the status stage. This workaround should be removed once all UDC drivers are fixed to always delay the status stage until a response is queued to EP0. Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/a8d2b91f9890dc21daa359183e84879ff4525180.1693237258.git.andreyknvl@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/legacy/inode.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index ce9e31f3d26b..6b929defc2d2 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -31,6 +31,12 @@
#include <linux/usb/gadgetfs.h>
#include <linux/usb/gadget.h>
+#include <linux/usb/composite.h> /* for USB_GADGET_DELAYED_STATUS */
+
+/* Undef helpers from linux/usb/composite.h as gadgetfs redefines them */
+#undef DBG
+#undef ERROR
+#undef INFO
/*
@@ -1511,7 +1517,16 @@ delegate:
event->u.setup = *ctrl;
ep0_readable (dev);
spin_unlock (&dev->lock);
- return 0;
+ /*
+ * Return USB_GADGET_DELAYED_STATUS as a workaround to
+ * stop some UDC drivers (e.g. dwc3) from automatically
+ * proceeding with the status stage for 0-length
+ * transfers.
+ * Should be removed once all UDC drivers are fixed to
+ * always delay the status stage until a response is
+ * queued to EP0.
+ */
+ return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0;
}
}