diff options
| author | Thomas Zimmermann | 2021-03-03 14:32:29 +0100 |
|---|---|---|
| committer | Maarten Lankhorst | 2021-03-11 11:11:33 +0100 |
| commit | 659ab7a49cbebe0deffcbe1f9560e82006b21817 (patch) | |
| tree | 6a74286e56b6257f68e6bbee23389469acd25408 /include/linux | |
| parent | 301469c121bfe4a243460ed0b6abf391139c6bb1 (diff) | |
drm: Use USB controller's DMA mask when importing dmabufs
USB devices cannot perform DMA and hence have no dma_mask set in their
device structure. Therefore importing dmabuf into a USB-based driver
fails, which breaks joining and mirroring of display in X11.
For USB devices, pick the associated USB controller as attachment device.
This allows the DRM import helpers to perform the DMA setup. If the DMA
controller does not support DMA transfers, we're out of luck and cannot
import. Our current USB-based DRM drivers don't use DMA, so the actual
DMA device is not important.
Tested by joining/mirroring displays of udl and radeon under Gnome/X11.
v8:
* release dmadev if device initialization fails (Noralf)
* fix commit description (Noralf)
v7:
* fix use-before-init bug in gm12u320 (Dan)
v6:
* implement workaround in DRM drivers and hold reference to
DMA device while USB device is in use
* remove dev_is_usb() (Greg)
* collapse USB helper into usb_intf_get_dma_device() (Alan)
* integrate Daniel's TODO statement (Daniel)
* fix typos (Greg)
v5:
* provide a helper for USB interfaces (Alan)
* add FIXME item to documentation and TODO list (Daniel)
v4:
* implement workaround with USB helper functions (Greg)
* use struct usb_device->bus->sysdev as DMA device (Takashi)
v3:
* drop gem_create_object
* use DMA mask of USB controller, if any (Daniel, Christian, Noralf)
v2:
* move fix to importer side (Christian, Daniel)
* update SHMEM and CMA helpers for new PRIME callbacks
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 6eb0233ec2d0 ("usb: don't inherity DMA properties for USB devices")
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303133229.3288-1-tzimmermann@suse.de
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/usb.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h index 7d72c4e0713c..d6a41841b93e 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -746,6 +746,8 @@ extern int usb_lock_device_for_reset(struct usb_device *udev, extern int usb_reset_device(struct usb_device *dev); extern void usb_queue_reset_device(struct usb_interface *dev); +extern struct device *usb_intf_get_dma_device(struct usb_interface *intf); + #ifdef CONFIG_ACPI extern int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable); |