From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/vhost/test.c | 379 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 379 insertions(+) create mode 100644 drivers/vhost/test.c (limited to 'drivers/vhost/test.c') diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c new file mode 100644 index 000000000..24514c8fd --- /dev/null +++ b/drivers/vhost/test.c @@ -0,0 +1,379 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2009 Red Hat, Inc. + * Author: Michael S. Tsirkin + * + * test virtio server in host kernel. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "test.h" +#include "vhost.h" + +/* Max number of bytes transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others. */ +#define VHOST_TEST_WEIGHT 0x80000 + +/* Max number of packets transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others with + * pkts. + */ +#define VHOST_TEST_PKT_WEIGHT 256 + +static const int vhost_test_bits[] = { + VHOST_FEATURES +}; + +#define VHOST_TEST_FEATURES VHOST_FEATURES_U64(vhost_test_bits, 0) + +enum { + VHOST_TEST_VQ = 0, + VHOST_TEST_VQ_MAX = 1, +}; + +struct vhost_test { + struct vhost_dev dev; + struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX]; +}; + +/* Expects to be always run from workqueue - which acts as + * read-size critical section for our kind of RCU. */ +static void handle_vq(struct vhost_test *n) +{ + struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ]; + unsigned out, in; + int head; + size_t len, total_len = 0; + void *private; + + mutex_lock(&vq->mutex); + private = vhost_vq_get_backend(vq); + if (!private) { + mutex_unlock(&vq->mutex); + return; + } + + vhost_disable_notify(&n->dev, vq); + + for (;;) { + head = vhost_get_vq_desc(vq, vq->iov, + ARRAY_SIZE(vq->iov), + &out, &in, + NULL, NULL); + /* On error, stop handling until the next kick. */ + if (unlikely(head < 0)) + break; + /* Nothing new? Wait for eventfd to tell us they refilled. */ + if (head == vq->num) { + if (unlikely(vhost_enable_notify(&n->dev, vq))) { + vhost_disable_notify(&n->dev, vq); + continue; + } + break; + } + if (in) { + vq_err(vq, "Unexpected descriptor format for TX: " + "out %d, int %d\n", out, in); + break; + } + len = iov_length(vq->iov, out); + /* Sanity check */ + if (!len) { + vq_err(vq, "Unexpected 0 len for TX\n"); + break; + } + vhost_add_used_and_signal(&n->dev, vq, head, 0); + total_len += len; + if (unlikely(vhost_exceeds_weight(vq, 0, total_len))) + break; + } + + mutex_unlock(&vq->mutex); +} + +static void handle_vq_kick(struct vhost_work *work) +{ + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, + poll.work); + struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev); + + handle_vq(n); +} + +static int vhost_test_open(struct inode *inode, struct file *f) +{ + struct vhost_test *n = kmalloc_obj(*n); + struct vhost_dev *dev; + struct vhost_virtqueue **vqs; + + if (!n) + return -ENOMEM; + vqs = kmalloc_objs(*vqs, VHOST_TEST_VQ_MAX); + if (!vqs) { + kfree(n); + return -ENOMEM; + } + + dev = &n->dev; + vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ]; + n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick; + vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV, + VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL); + + f->private_data = n; + + return 0; +} + +static void *vhost_test_stop_vq(struct vhost_test *n, + struct vhost_virtqueue *vq) +{ + void *private; + + mutex_lock(&vq->mutex); + private = vhost_vq_get_backend(vq); + vhost_vq_set_backend(vq, NULL); + mutex_unlock(&vq->mutex); + return private; +} + +static void vhost_test_stop(struct vhost_test *n, void **privatep) +{ + *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ); +} + +static void vhost_test_flush(struct vhost_test *n) +{ + vhost_dev_flush(&n->dev); +} + +static int vhost_test_release(struct inode *inode, struct file *f) +{ + struct vhost_test *n = f->private_data; + void *private; + + vhost_test_stop(n, &private); + vhost_test_flush(n); + vhost_dev_stop(&n->dev); + vhost_dev_cleanup(&n->dev); + kfree(n->dev.vqs); + kfree(n); + return 0; +} + +static long vhost_test_run(struct vhost_test *n, int test) +{ + void *priv, *oldpriv; + struct vhost_virtqueue *vq; + int r, index; + + if (test < 0 || test > 1) + return -EINVAL; + + mutex_lock(&n->dev.mutex); + r = vhost_dev_check_owner(&n->dev); + if (r) + goto err; + + for (index = 0; index < n->dev.nvqs; ++index) { + /* Verify that ring has been setup correctly. */ + if (!vhost_vq_access_ok(&n->vqs[index])) { + r = -EFAULT; + goto err; + } + } + + for (index = 0; index < n->dev.nvqs; ++index) { + vq = n->vqs + index; + mutex_lock(&vq->mutex); + priv = test ? n : NULL; + + /* start polling new socket */ + oldpriv = vhost_vq_get_backend(vq); + vhost_vq_set_backend(vq, priv); + + r = vhost_vq_init_access(&n->vqs[index]); + + mutex_unlock(&vq->mutex); + + if (r) + goto err; + + if (oldpriv) { + vhost_test_flush(n); + } + } + + mutex_unlock(&n->dev.mutex); + return 0; + +err: + mutex_unlock(&n->dev.mutex); + return r; +} + +static long vhost_test_reset_owner(struct vhost_test *n) +{ + void *priv = NULL; + long err; + struct vhost_iotlb *umem; + + mutex_lock(&n->dev.mutex); + err = vhost_dev_check_owner(&n->dev); + if (err) + goto done; + umem = vhost_dev_reset_owner_prepare(); + if (!umem) { + err = -ENOMEM; + goto done; + } + vhost_test_stop(n, &priv); + vhost_test_flush(n); + vhost_dev_stop(&n->dev); + vhost_dev_reset_owner(&n->dev, umem); +done: + mutex_unlock(&n->dev.mutex); + return err; +} + +static int vhost_test_set_features(struct vhost_test *n, u64 features) +{ + struct vhost_virtqueue *vq; + + mutex_lock(&n->dev.mutex); + if ((features & (1 << VHOST_F_LOG_ALL)) && + !vhost_log_access_ok(&n->dev)) { + mutex_unlock(&n->dev.mutex); + return -EFAULT; + } + vq = &n->vqs[VHOST_TEST_VQ]; + mutex_lock(&vq->mutex); + vq->acked_features = features; + mutex_unlock(&vq->mutex); + mutex_unlock(&n->dev.mutex); + return 0; +} + +static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd) +{ + static void *backend; + + const bool enable = fd != -1; + struct vhost_virtqueue *vq; + int r; + + mutex_lock(&n->dev.mutex); + r = vhost_dev_check_owner(&n->dev); + if (r) + goto err; + + if (index >= VHOST_TEST_VQ_MAX) { + r = -ENOBUFS; + goto err; + } + vq = &n->vqs[index]; + mutex_lock(&vq->mutex); + + /* Verify that ring has been setup correctly. */ + if (!vhost_vq_access_ok(vq)) { + r = -EFAULT; + goto err_vq; + } + if (!enable) { + vhost_poll_stop(&vq->poll); + backend = vhost_vq_get_backend(vq); + vhost_vq_set_backend(vq, NULL); + } else { + vhost_vq_set_backend(vq, backend); + r = vhost_vq_init_access(vq); + if (r == 0) + r = vhost_poll_start(&vq->poll, vq->kick); + } + + mutex_unlock(&vq->mutex); + + if (enable) { + vhost_test_flush(n); + } + + mutex_unlock(&n->dev.mutex); + return 0; + +err_vq: + mutex_unlock(&vq->mutex); +err: + mutex_unlock(&n->dev.mutex); + return r; +} + +static long vhost_test_ioctl(struct file *f, unsigned int ioctl, + unsigned long arg) +{ + struct vhost_vring_file backend; + struct vhost_test *n = f->private_data; + void __user *argp = (void __user *)arg; + u64 __user *featurep = argp; + int test; + u64 features; + int r; + switch (ioctl) { + case VHOST_TEST_RUN: + if (copy_from_user(&test, argp, sizeof test)) + return -EFAULT; + return vhost_test_run(n, test); + case VHOST_TEST_SET_BACKEND: + if (copy_from_user(&backend, argp, sizeof backend)) + return -EFAULT; + return vhost_test_set_backend(n, backend.index, backend.fd); + case VHOST_GET_FEATURES: + features = VHOST_TEST_FEATURES; + if (copy_to_user(featurep, &features, sizeof features)) + return -EFAULT; + return 0; + case VHOST_SET_FEATURES: + if (copy_from_user(&features, featurep, sizeof features)) + return -EFAULT; + if (features & ~VHOST_TEST_FEATURES) + return -EOPNOTSUPP; + return vhost_test_set_features(n, features); + case VHOST_RESET_OWNER: + return vhost_test_reset_owner(n); + default: + mutex_lock(&n->dev.mutex); + r = vhost_dev_ioctl(&n->dev, ioctl, argp); + if (r == -ENOIOCTLCMD) + r = vhost_vring_ioctl(&n->dev, ioctl, argp); + vhost_test_flush(n); + mutex_unlock(&n->dev.mutex); + return r; + } +} + +static const struct file_operations vhost_test_fops = { + .owner = THIS_MODULE, + .release = vhost_test_release, + .unlocked_ioctl = vhost_test_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .open = vhost_test_open, + .llseek = noop_llseek, +}; + +static struct miscdevice vhost_test_misc = { + MISC_DYNAMIC_MINOR, + "vhost-test", + &vhost_test_fops, +}; +module_misc_device(vhost_test_misc); + +MODULE_VERSION("0.0.1"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Michael S. Tsirkin"); +MODULE_DESCRIPTION("Host kernel side for virtio simulator"); -- cgit v1.3.1