Fix URB buffer allocation of pwc driver (rhbz 1918778)

Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>

2 files changed, 62 insertions, 0 deletions

diff --git a/kernel.spec b/kernel.spec
index b116f377d..d2c6ebf0e 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -852,6 +852,9 @@ Patch104: 0001-brcm-rpi4-fix-usb-numeration.patch
 # Nouveau mDP detection fix
 Patch107: 0001-drm-nouveau-kms-handle-mDP-connectors.patch
 
+# rhbz 1918778
+Patch108: media-pwc-fix-the-urb-buffer-allocation.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -2967,6 +2970,7 @@ fi
 %changelog
 * Wed Jan 27 08:07:52 CST 2021 Justin M. Forbes <jforbes@fedoraproject.org> - 5.10.11-100
 - Linux v5.10.11
+- Fix URB buffer allocation of pwc driver (rhbz 1918778)
 
 * Sun Jan 24 11:29:01 CST 2021 Justin M. Forbes <jforbes@fedoraproject.org> - 5.10.10-100
 - Linux v5.10.10
diff --git a/media-pwc-fix-the-urb-buffer-allocation.patch b/media-pwc-fix-the-urb-buffer-allocation.patch
new file mode 100644
index 000000000..413868bfb
--- /dev/null
+++ b/media-pwc-fix-the-urb-buffer-allocation.patch
@@ -0,0 +1,58 @@
+From MAILER-DAEMON Wed Jan 27 14:16:57 2021
+From: Takashi Iwai <tiwai@suse.de>
+To: Hans Verkuil <hverkuil@xs4all.nl>
+Cc: Mauro Carvalho Chehab <mchehab@kernel.org>, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
+Subject: [PATCH] media: pwc: Fix the URB buffer allocation
+Date: Thu, 21 Jan 2021 21:28:55 +0100
+Message-Id: <20210121202855.17400-1-tiwai@suse.de>
+List-ID: <linux-media.vger.kernel.org>
+X-Mailing-List: linux-media@vger.kernel.org
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 7bit
+
+The URB buffer allocation of pwc driver involves with the
+dma_map_single(), and it needs to pass the right device.  Currently it
+passes usb_device.dev, but it's no real device that manages the DMA.
+Since the passed device has no DMA mask set up, now the pwc driver
+hits the WARN_ON_ONCE() check in dma_map_page_attrs() (that was
+introduced in 5.10), resulting in an error at URB allocations.
+Eventually this ended up with the black output.
+
+This patch fixes the bug by passing the proper device, the bus
+controller, to make the URB allocation and map working again.
+
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+Reviewed-by: Robert Foss <robert.foss@linaro.org>
+Cc: <stable@vger.kernel.org>
+BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1181133
+---
+ drivers/media/usb/pwc/pwc-if.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
+index 61869636ec61..d771160bb168 100644
+--- a/drivers/media/usb/pwc/pwc-if.c
++++ b/drivers/media/usb/pwc/pwc-if.c
+@@ -461,7 +461,7 @@ static int pwc_isoc_init(struct pwc_device *pdev)
+ 		urb->pipe = usb_rcvisocpipe(udev, pdev->vendpoint);
+ 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+ 		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
+-		urb->transfer_buffer = pwc_alloc_urb_buffer(&udev->dev,
++		urb->transfer_buffer = pwc_alloc_urb_buffer(udev->bus->controller,
+ 							    urb->transfer_buffer_length,
+ 							    &urb->transfer_dma);
+ 		if (urb->transfer_buffer == NULL) {
+@@ -524,7 +524,7 @@ static void pwc_iso_free(struct pwc_device *pdev)
+ 		if (urb) {
+ 			PWC_DEBUG_MEMORY("Freeing URB\n");
+ 			if (urb->transfer_buffer)
+-				pwc_free_urb_buffer(&urb->dev->dev,
++				pwc_free_urb_buffer(urb->dev->bus->controller,
+ 						    urb->transfer_buffer_length,
+ 						    urb->transfer_buffer,
+ 						    urb->transfer_dma);
+-- 
+2.26.2
+
+