From 862b416560c348f66d2091c56e71fd5462510cab Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Tue, 2 Apr 2024 13:09:51 +0200 Subject: usb: gadget: functionfs: Wait for fences before enqueueing DMABUF Instead of bailing when fences have already been installed on the DMABUF, wait for them (with a timeout) when doing a blocking operation. This fixes the issue where userspace would submit a DMABUF with fences already installed, with the (correct) expectation that it would just work. Fixes: 7b07a2a7ca02 ("usb: gadget: functionfs: Add DMABUF import interface") Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20240402110951.16376-3-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_fs.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'drivers/usb') diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 70e8532127ad..f855f1fc8e5e 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -46,6 +46,8 @@ #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ +#define DMABUF_ENQUEUE_TIMEOUT_MS 5000 + MODULE_IMPORT_NS(DMA_BUF); /* Reference counter handling */ @@ -1580,9 +1582,11 @@ static int ffs_dmabuf_transfer(struct file *file, struct usb_request *usb_req; enum dma_resv_usage resv_dir; struct dma_buf *dmabuf; + unsigned long timeout; struct ffs_ep *ep; bool cookie; u32 seqno; + long retl; int ret; if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK) @@ -1616,17 +1620,14 @@ static int ffs_dmabuf_transfer(struct file *file, goto err_attachment_put; /* Make sure we don't have writers */ - if (!dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_WRITE)) { - pr_vdebug("FFS WRITE fence is not signaled\n"); - ret = -EBUSY; - goto err_resv_unlock; - } - - /* If we're writing to the DMABUF, make sure we don't have readers */ - if (epfile->in && - !dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_READ)) { - pr_vdebug("FFS READ fence is not signaled\n"); - ret = -EBUSY; + timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS); + retl = dma_resv_wait_timeout(dmabuf->resv, + dma_resv_usage_rw(epfile->in), + true, timeout); + if (retl == 0) + retl = -EBUSY; + if (retl < 0) { + ret = (int)retl; goto err_resv_unlock; } -- cgit v1.2.3