This is a note to let you know that I've just added the patch titled usb: dwc2: Fix gadget DMA unmap direction to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-dwc2-fix-gadget-dma-unmap-direction.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 75a41ce46bae6cbe7d3bb2584eb844291d642874 Mon Sep 17 00:00:00 2001 From: Phil Elwell <phil@xxxxxxxxxxxxxxx> Date: Thu, 6 May 2021 12:22:00 +0100 Subject: usb: dwc2: Fix gadget DMA unmap direction From: Phil Elwell <phil@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210506112200.2893922-1-phil@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/dwc2/core.h | 2 ++ drivers/usb/dwc2/gadget.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) --- 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; --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -289,7 +289,7 @@ static void dwc2_hsotg_unmap_dma(struct 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 dwc 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; Patches currently in stable-queue which might be from phil@xxxxxxxxxxxxxxx are queue-4.4/usb-dwc2-fix-gadget-dma-unmap-direction.patch