usb: dwc2: Fix gadget DMA unmap direction

commit 75a41ce46bae6cbe7d3bb2584eb844291d642874 upstream.

The dwc2 gadget support maps and unmaps DMA buffers as necessary. When
mapping and unmapping it uses the direction of the endpoint to select
the direction of the DMA transfer, but this fails for Control OUT
transfers because the unmap occurs after the endpoint direction has
been reversed for the status phase.

A possible solution would be to unmap the buffer before the direction
is changed, but a safer, less invasive fix is to remember the buffer
direction independently of the endpoint direction.

Fixes: fe0b94abcdf6 ("usb: dwc2: gadget: manage ep0 state in software")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Link: https://lore.kernel.org/r/20210506112200.2893922-1-phil@raspberrypi.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index a899d47c2a7cb6723c3e72c4d2bbb1800a301cf3..ecc4d09ea70400a58b9d3caaa2db45e7747ff05c 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -144,6 +144,7 @@ struct dwc2_hsotg_req;
  * @lock: State lock to protect contents of endpoint.
  * @dir_in: Set to true if this endpoint is of the IN direction, which
  *          means that it is sending data to the Host.
+ * @map_dir: Set to the value of dir_in when the DMA buffer is mapped.
  * @index: The index for the endpoint registers.
  * @mc: Multi Count - number of transactions per microframe
  * @interval - Interval for periodic endpoints
@@ -185,6 +186,7 @@ struct dwc2_hsotg_ep {
        unsigned short          fifo_index;
 
        unsigned char           dir_in;
+       unsigned char           map_dir;
        unsigned char           index;
        unsigned char           mc;
        u16                     interval;

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 135e97310f1182853fbe98fce1eaba0a7b5382bf..ab5cde515b1dee45a94f54c57ee0cb3bef0a1870 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -289,7 +289,7 @@ static void dwc2_hsotg_unmap_dma(struct dwc2_hsotg *hsotg,
        if (hs_req->req.length == 0)
                return;
 
-       usb_gadget_unmap_request(&hsotg->gadget, req, hs_ep->dir_in);
+       usb_gadget_unmap_request(&hsotg->gadget, req, hs_ep->map_dir);
 }
 
 /**
@@ -707,6 +707,7 @@ static int dwc2_hsotg_map_dma(struct dwc2_hsotg *hsotg,
        if (hs_req->req.length == 0)
                return 0;
 
+       hs_ep->map_dir = hs_ep->dir_in;
        ret = usb_gadget_map_request(&hsotg->gadget, req, hs_ep->dir_in);
        if (ret)
                goto dma_error;