Workaround for low volume with Apple USB-C to 3.5mm Adapter

arch/arm64/configs/floral_defconfig

@@ -43,8 +43,6 @@ CONFIG_PROFILING=y
 CONFIG_JUMP_LABEL=y
 CONFIG_CC_STACKPROTECTOR_STRONG=y
 # CONFIG_THINLTO is not set
-CONFIG_LTO_CLANG=y
-CONFIG_CFI_CLANG=y
 CONFIG_SHADOW_CALL_STACK=y
 CONFIG_REFCOUNT_FULL=y
 CONFIG_MODULES=y
@@ -531,6 +529,7 @@ CONFIG_USB_CONFIGFS_F_CDEV=y
 CONFIG_USB_CONFIGFS_F_CCID=y
 CONFIG_USB_CONFIGFS_F_GSI=y
 CONFIG_USB_CONFIGFS_F_QDSS=y
+CONFIG_USB_CONFIGFS_F_UVC=y
 CONFIG_TYPEC=y
 CONFIG_TYPEC_TCPM=y
 CONFIG_USB_PD_ENGINE=y

arch/arm64/configs/sunfish_defconfig

@@ -43,8 +43,6 @@ CONFIG_PROFILING=y
 CONFIG_JUMP_LABEL=y
 CONFIG_CC_STACKPROTECTOR_STRONG=y
 # CONFIG_THINLTO is not set
-CONFIG_LTO_CLANG=y
-CONFIG_CFI_CLANG=y
 CONFIG_SHADOW_CALL_STACK=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
@@ -524,6 +522,7 @@ CONFIG_USB_CONFIGFS_F_CDEV=y
 CONFIG_USB_CONFIGFS_F_CCID=y
 CONFIG_USB_CONFIGFS_F_GSI=y
 CONFIG_USB_CONFIGFS_F_QDSS=y
+CONFIG_USB_CONFIGFS_F_UVC=y
 CONFIG_TYPEC=y
 CONFIG_TYPEC_TCPM=y
 CONFIG_USB_PD_ENGINE=y

drivers/media/usb/uvc/uvc_ctrl.c

@@ -22,6 +22,7 @@
 #include <linux/wait.h>
 #include <linux/atomic.h>
 #include <media/v4l2-ctrls.h>
+#include <media/v4l2-uvc.h>
 
 #include "uvcvideo.h"
 

drivers/media/usb/uvc/uvc_driver.c

@@ -24,6 +24,7 @@
 #include <asm/unaligned.h>
 
 #include <media/v4l2-common.h>
+#include <media/v4l2-uvc.h>
 
 #include "uvcvideo.h"
 
@@ -38,173 +39,6 @@ static unsigned int uvc_quirks_param = -1;
 unsigned int uvc_trace_param;
 unsigned int uvc_timeout_param = UVC_CTRL_STREAMING_TIMEOUT;
 
-/* ------------------------------------------------------------------------
- * Video formats
- */
-
-static struct uvc_format_desc uvc_fmts[] = {
-	{
-		.name		= "YUV 4:2:2 (YUYV)",
-		.guid		= UVC_GUID_FORMAT_YUY2,
-		.fcc		= V4L2_PIX_FMT_YUYV,
-	},
-	{
-		.name		= "YUV 4:2:2 (YUYV)",
-		.guid		= UVC_GUID_FORMAT_YUY2_ISIGHT,
-		.fcc		= V4L2_PIX_FMT_YUYV,
-	},
-	{
-		.name		= "YUV 4:2:0 (NV12)",
-		.guid		= UVC_GUID_FORMAT_NV12,
-		.fcc		= V4L2_PIX_FMT_NV12,
-	},
-	{
-		.name		= "MJPEG",
-		.guid		= UVC_GUID_FORMAT_MJPEG,
-		.fcc		= V4L2_PIX_FMT_MJPEG,
-	},
-	{
-		.name		= "YVU 4:2:0 (YV12)",
-		.guid		= UVC_GUID_FORMAT_YV12,
-		.fcc		= V4L2_PIX_FMT_YVU420,
-	},
-	{
-		.name		= "YUV 4:2:0 (I420)",
-		.guid		= UVC_GUID_FORMAT_I420,
-		.fcc		= V4L2_PIX_FMT_YUV420,
-	},
-	{
-		.name		= "YUV 4:2:0 (M420)",
-		.guid		= UVC_GUID_FORMAT_M420,
-		.fcc		= V4L2_PIX_FMT_M420,
-	},
-	{
-		.name		= "YUV 4:2:2 (UYVY)",
-		.guid		= UVC_GUID_FORMAT_UYVY,
-		.fcc		= V4L2_PIX_FMT_UYVY,
-	},
-	{
-		.name		= "Greyscale 8-bit (Y800)",
-		.guid		= UVC_GUID_FORMAT_Y800,
-		.fcc		= V4L2_PIX_FMT_GREY,
-	},
-	{
-		.name		= "Greyscale 8-bit (Y8  )",
-		.guid		= UVC_GUID_FORMAT_Y8,
-		.fcc		= V4L2_PIX_FMT_GREY,
-	},
-	{
-		.name		= "Greyscale 10-bit (Y10 )",
-		.guid		= UVC_GUID_FORMAT_Y10,
-		.fcc		= V4L2_PIX_FMT_Y10,
-	},
-	{
-		.name		= "Greyscale 12-bit (Y12 )",
-		.guid		= UVC_GUID_FORMAT_Y12,
-		.fcc		= V4L2_PIX_FMT_Y12,
-	},
-	{
-		.name		= "Greyscale 16-bit (Y16 )",
-		.guid		= UVC_GUID_FORMAT_Y16,
-		.fcc		= V4L2_PIX_FMT_Y16,
-	},
-	{
-		.name		= "BGGR Bayer (BY8 )",
-		.guid		= UVC_GUID_FORMAT_BY8,
-		.fcc		= V4L2_PIX_FMT_SBGGR8,
-	},
-	{
-		.name		= "BGGR Bayer (BA81)",
-		.guid		= UVC_GUID_FORMAT_BA81,
-		.fcc		= V4L2_PIX_FMT_SBGGR8,
-	},
-	{
-		.name		= "GBRG Bayer (GBRG)",
-		.guid		= UVC_GUID_FORMAT_GBRG,
-		.fcc		= V4L2_PIX_FMT_SGBRG8,
-	},
-	{
-		.name		= "GRBG Bayer (GRBG)",
-		.guid		= UVC_GUID_FORMAT_GRBG,
-		.fcc		= V4L2_PIX_FMT_SGRBG8,
-	},
-	{
-		.name		= "RGGB Bayer (RGGB)",
-		.guid		= UVC_GUID_FORMAT_RGGB,
-		.fcc		= V4L2_PIX_FMT_SRGGB8,
-	},
-	{
-		.name		= "RGB565",
-		.guid		= UVC_GUID_FORMAT_RGBP,
-		.fcc		= V4L2_PIX_FMT_RGB565,
-	},
-	{
-		.name		= "BGR 8:8:8 (BGR3)",
-		.guid		= UVC_GUID_FORMAT_BGR3,
-		.fcc		= V4L2_PIX_FMT_BGR24,
-	},
-	{
-		.name		= "H.264",
-		.guid		= UVC_GUID_FORMAT_H264,
-		.fcc		= V4L2_PIX_FMT_H264,
-	},
-	{
-		.name		= "Greyscale 8 L/R (Y8I)",
-		.guid		= UVC_GUID_FORMAT_Y8I,
-		.fcc		= V4L2_PIX_FMT_Y8I,
-	},
-	{
-		.name		= "Greyscale 12 L/R (Y12I)",
-		.guid		= UVC_GUID_FORMAT_Y12I,
-		.fcc		= V4L2_PIX_FMT_Y12I,
-	},
-	{
-		.name		= "Depth data 16-bit (Z16)",
-		.guid		= UVC_GUID_FORMAT_Z16,
-		.fcc		= V4L2_PIX_FMT_Z16,
-	},
-	{
-		.name		= "Bayer 10-bit (SRGGB10P)",
-		.guid		= UVC_GUID_FORMAT_RW10,
-		.fcc		= V4L2_PIX_FMT_SRGGB10P,
-	},
-	{
-		.name		= "Bayer 16-bit (SBGGR16)",
-		.guid		= UVC_GUID_FORMAT_BG16,
-		.fcc		= V4L2_PIX_FMT_SBGGR16,
-	},
-	{
-		.name		= "Bayer 16-bit (SGBRG16)",
-		.guid		= UVC_GUID_FORMAT_GB16,
-		.fcc		= V4L2_PIX_FMT_SGBRG16,
-	},
-	{
-		.name		= "Bayer 16-bit (SRGGB16)",
-		.guid		= UVC_GUID_FORMAT_RG16,
-		.fcc		= V4L2_PIX_FMT_SRGGB16,
-	},
-	{
-		.name		= "Bayer 16-bit (SGRBG16)",
-		.guid		= UVC_GUID_FORMAT_GR16,
-		.fcc		= V4L2_PIX_FMT_SGRBG16,
-	},
-	{
-		.name		= "Depth data 16-bit (Z16)",
-		.guid		= UVC_GUID_FORMAT_INVZ,
-		.fcc		= V4L2_PIX_FMT_Z16,
-	},
-	{
-		.name		= "Greyscale 10-bit (Y10 )",
-		.guid		= UVC_GUID_FORMAT_INVI,
-		.fcc		= V4L2_PIX_FMT_Y10,
-	},
-	{
-		.name		= "IR:Depth 26-bit (INZI)",
-		.guid		= UVC_GUID_FORMAT_INZI,
-		.fcc		= V4L2_PIX_FMT_INZI,
-	},
-};
-
 /* ------------------------------------------------------------------------
  * Utility functions
  */
@@ -224,19 +58,6 @@ struct usb_host_endpoint *uvc_find_endpoint(struct usb_host_interface *alts,
 	return NULL;
 }
 
-static struct uvc_format_desc *uvc_format_by_guid(const __u8 guid[16])
-{
-	unsigned int len = ARRAY_SIZE(uvc_fmts);
-	unsigned int i;
-
-	for (i = 0; i < len; ++i) {
-		if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
-			return &uvc_fmts[i];
-	}
-
-	return NULL;
-}
-
 static __u32 uvc_colorspace(const __u8 primaries)
 {
 	static const __u8 colorprimaries[] = {
@@ -254,86 +75,6 @@ static __u32 uvc_colorspace(const __u8 primaries)
 	return 0;
 }
 
-/* Simplify a fraction using a simple continued fraction decomposition. The
- * idea here is to convert fractions such as 333333/10000000 to 1/30 using
- * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
- * arbitrary parameters to remove non-significative terms from the simple
- * continued fraction decomposition. Using 8 and 333 for n_terms and threshold
- * respectively seems to give nice results.
- */
-void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
-		unsigned int n_terms, unsigned int threshold)
-{
-	uint32_t *an;
-	uint32_t x, y, r;
-	unsigned int i, n;
-
-	an = kmalloc(n_terms * sizeof *an, GFP_KERNEL);
-	if (an == NULL)
-		return;
-
-	/* Convert the fraction to a simple continued fraction. See
-	 * http://mathforum.org/dr.math/faq/faq.fractions.html
-	 * Stop if the current term is bigger than or equal to the given
-	 * threshold.
-	 */
-	x = *numerator;
-	y = *denominator;
-
-	for (n = 0; n < n_terms && y != 0; ++n) {
-		an[n] = x / y;
-		if (an[n] >= threshold) {
-			if (n < 2)
-				n++;
-			break;
-		}
-
-		r = x - an[n] * y;
-		x = y;
-		y = r;
-	}
-
-	/* Expand the simple continued fraction back to an integer fraction. */
-	x = 0;
-	y = 1;
-
-	for (i = n; i > 0; --i) {
-		r = y;
-		y = an[i-1] * y + x;
-		x = r;
-	}
-
-	*numerator = y;
-	*denominator = x;
-	kfree(an);
-}
-
-/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
- * to compute numerator / denominator * 10000000 using 32 bit fixed point
- * arithmetic only.
- */
-uint32_t uvc_fraction_to_interval(uint32_t numerator, uint32_t denominator)
-{
-	uint32_t multiplier;
-
-	/* Saturate the result if the operation would overflow. */
-	if (denominator == 0 ||
-	    numerator/denominator >= ((uint32_t)-1)/10000000)
-		return (uint32_t)-1;
-
-	/* Divide both the denominator and the multiplier by two until
-	 * numerator * multiplier doesn't overflow. If anyone knows a better
-	 * algorithm please let me know.
-	 */
-	multiplier = 10000000;
-	while (numerator > ((uint32_t)-1)/multiplier) {
-		multiplier /= 2;
-		denominator /= 2;
-	}
-
-	return denominator ? numerator * multiplier / denominator : 0;
-}
-
 /* ------------------------------------------------------------------------
  * Terminal and unit management
  */

drivers/media/usb/uvc/uvc_v4l2.c

@@ -376,7 +376,7 @@ static int uvc_v4l2_get_streamparm(struct uvc_streaming *stream,
 	mutex_unlock(&stream->mutex);
 
 	denominator = 10000000;
-	uvc_simplify_fraction(&numerator, &denominator, 8, 333);
+	v4l2_simplify_fraction(&numerator, &denominator, 8, 333);
 
 	memset(parm, 0, sizeof *parm);
 	parm->type = stream->type;
@@ -414,7 +414,7 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
 	else
 		timeperframe = parm->parm.output.timeperframe;
 
-	interval = uvc_fraction_to_interval(timeperframe.numerator,
+	interval = v4l2_fraction_to_interval(timeperframe.numerator,
 		timeperframe.denominator);
 	uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
 		timeperframe.numerator, timeperframe.denominator, interval);
@@ -443,7 +443,7 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
 	/* Return the actual frame period. */
 	timeperframe.numerator = probe.dwFrameInterval;
 	timeperframe.denominator = 10000000;
-	uvc_simplify_fraction(&timeperframe.numerator,
+	v4l2_simplify_fraction(&timeperframe.numerator,
 		&timeperframe.denominator, 8, 333);
 
 	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
@@ -1256,7 +1256,7 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 		fival->discrete.numerator =
 			frame->dwFrameInterval[fival->index];
 		fival->discrete.denominator = 10000000;
-		uvc_simplify_fraction(&fival->discrete.numerator,
+		v4l2_simplify_fraction(&fival->discrete.numerator,
 			&fival->discrete.denominator, 8, 333);
 	} else {
 		if (fival->index)
@@ -1269,11 +1269,11 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 		fival->stepwise.max.denominator = 10000000;
 		fival->stepwise.step.numerator = frame->dwFrameInterval[2];
 		fival->stepwise.step.denominator = 10000000;
-		uvc_simplify_fraction(&fival->stepwise.min.numerator,
+		v4l2_simplify_fraction(&fival->stepwise.min.numerator,
 			&fival->stepwise.min.denominator, 8, 333);
-		uvc_simplify_fraction(&fival->stepwise.max.numerator,
+		v4l2_simplify_fraction(&fival->stepwise.max.numerator,
 			&fival->stepwise.max.denominator, 8, 333);
-		uvc_simplify_fraction(&fival->stepwise.step.numerator,
+		v4l2_simplify_fraction(&fival->stepwise.step.numerator,
 			&fival->stepwise.step.denominator, 8, 333);
 	}