1 files changed, 26 insertions, 11 deletions

diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index a694e1c42fdf..ae35e7d22e73 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -347,6 +347,8 @@ static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
         __le32 data;
         int err, cur_rate, prev_rate;
         int clock;
+        bool writeable;
+        struct uac_clock_source_descriptor *cs_desc;
 
         clock = snd_usb_clock_find_source(chip, fmt->clock, true);
         if (clock < 0)
@@ -354,20 +356,33 @@ static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 
         prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
 
-        data = cpu_to_le32(rate);
-        if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
-                                   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
-                                   UAC2_CS_CONTROL_SAM_FREQ << 8,
-                                   snd_usb_ctrl_intf(chip) | (clock << 8),
-                                   &data, sizeof(data))) < 0) {
-                snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2): err %d\n",
-                           dev->devnum, iface, fmt->altsetting, rate, err);
-                return err;
-        }
+        cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
+        writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
+        if (writeable) {
+                data = cpu_to_le32(rate);
+                err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
+                                      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
+                                      UAC2_CS_CONTROL_SAM_FREQ << 8,
+                                      snd_usb_ctrl_intf(chip) | (clock << 8),
+                                      &data, sizeof(data));
+                if (err < 0) {
+                        snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2): err %d\n",
+                                   dev->devnum, iface, fmt->altsetting, rate, err);
+                        return err;
+                }
 
-        cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
+                cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
+        } else {
+                cur_rate = prev_rate;
+        }
 
         if (cur_rate != rate) {
+                if (!writeable) {
+                        snd_printk(KERN_WARNING
+                                   "%d:%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
+                                   dev->devnum, iface, fmt->altsetting, rate, cur_rate);
+                        return -ENXIO;
+                }
                 snd_printd(KERN_WARNING
                            "current rate %d is different from the runtime rate %d\n",
                            cur_rate, rate);