[PATCH 1/3] usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks
From: Neill Kapron
Date: Sun Jun 14 2026 - 14:10:53 EST
When parsing endpoint descriptors, ffs_data_got_descs() generates the
eps_addrmap which contains the endpoint direction. However, epfile->in
was previously only populated in ffs_func_eps_enable() which executes
upon USB host connection. As a result, early userspace ioctls like
FUNCTIONFS_DMABUF_ATTACH that run before the host connects would see
epfile->in as 0, leading to incorrect DMA directions.
By moving the initialization to ffs_epfiles_create(), epfile->in is
accurate before userspace opens the endpoint files.
Fixes: 7b07a2a7ca02 ("usb: gadget: functionfs: Add DMABUF import interface")
Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Neill Kapron <nkapron@xxxxxxxxxx>
---
drivers/usb/gadget/function/f_fs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 75912ce6ab55..38e36faefe92 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -2364,6 +2364,7 @@ static int ffs_epfiles_create(struct ffs_data *ffs)
sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
else
sprintf(epfile->name, "ep%u", i);
+ epfile->in = (ffs->eps_addrmap[i] & USB_ENDPOINT_DIR_MASK) ? 1 : 0;
err = ffs_sb_create_file(ffs->sb, epfile->name,
epfile, &ffs_epfile_operations);
if (err) {
@@ -2453,7 +2454,6 @@ static int ffs_func_eps_enable(struct ffs_function *func)
ret = usb_ep_enable(ep->ep);
if (!ret) {
epfile->ep = ep;
- epfile->in = usb_endpoint_dir_in(ep->ep->desc);
epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
} else {
break;
--
2.54.0.1136.gdb2ca164c4-goog