drm/radeon: Do not implement mode_set_base_atomic callback

Remove the implementation of the CRTC helper mode_set_base_atomic
from radeon. It pretends to provide mode setting for kdb debugging,
but has been broken for some time.

Kdb output has been supported only for non-atomic mode setting since
commit 9c79e0b1d096 ("drm/fb-helper: Give up on kgdb for atomic drivers")
from 2017.

While radeon provides non-atomic mode setting, kdb assumes that the GEM
buffer object is at a fixed location in video memory. This assumption
currently blocks radeon from converting to generic fbdev emulation.
Fbdev-ttm helpers use a shadow buffer with a movable GEM buffer object.
Triggering kdb does therefore not update the display.

Another problem is that the current implementation does not handle
USB keyboard input. Therefore a serial terminal is required. Then when
continuing from the debugger, radeon fails with an error:

[7]kdb> go
[   40.345523][    C7] BUG: scheduling while atomic: bash/1580/0x00110003
[...]
[   40.345613][    C7]  schedule+0x27/0xd0
[   40.345615][    C7]  schedule_timeout+0x7b/0x100
[   40.345617][    C7]  ? __pfx_process_timeout+0x10/0x10
[   40.345619][    C7]  msleep+0x31/0x50
[   40.345621][    C7]  radeon_crtc_load_lut+0x2e4/0xcb0 [radeon 31c1ee785de120fcfd0babcc09babb3770252b4e]
[   40.345698][    C7]  radeon_crtc_gamma_set+0xe/0x20 [radeon 31c1ee785de120fcfd0babcc09babb3770252b4e]
[   40.345760][    C7]  drm_fb_helper_debug_leave+0xd8/0x130
[   40.345763][    C7]  kgdboc_post_exp_handler+0x54/0x70
[...]

and the system hangs.

Support for kdb feels pretty much broken. Hence remove the whole kdb
support from radeon.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20251125130634.1080966-4-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 9b3a3a9d60e2033f9c9070cb52409b919265a8ba..2fc0334e0d6c5f7614d2affa74404deeecea8b99 100644 (file)
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1133,7 +1133,7 @@ static void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode
 
 static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
                                 struct drm_framebuffer *fb,
-                                int x, int y, int atomic)
+                                int x, int y)
 {
        struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);
        struct drm_device *dev = crtc->dev;
@@ -1150,33 +1150,23 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
        bool bypass_lut = false;
 
        /* no fb bound */
-       if (!atomic && !crtc->primary->fb) {
+       if (!crtc->primary->fb) {
                DRM_DEBUG_KMS("No FB bound\n");
                return 0;
        }
 
-       if (atomic)
-               target_fb = fb;
-       else
-               target_fb = crtc->primary->fb;
+       target_fb = crtc->primary->fb;
 
-       /* If atomic, assume fb object is pinned & idle & fenced and
-        * just update base pointers
-        */
        obj = target_fb->obj[0];
        rbo = gem_to_radeon_bo(obj);
        r = radeon_bo_reserve(rbo, false);
        if (unlikely(r != 0))
                return r;
 
-       if (atomic)
-               fb_location = radeon_bo_gpu_offset(rbo);
-       else {
-               r = radeon_bo_pin(rbo, RADEON_GEM_DOMAIN_VRAM, &fb_location);
-               if (unlikely(r != 0)) {
-                       radeon_bo_unreserve(rbo);
-                       return -EINVAL;
-               }
+       r = radeon_bo_pin(rbo, RADEON_GEM_DOMAIN_VRAM, &fb_location);
+       if (unlikely(r != 0)) {
+               radeon_bo_unreserve(rbo);
+               return -EINVAL;
        }
 
        radeon_bo_get_tiling_flags(rbo, &tiling_flags, NULL);
@@ -1437,7 +1427,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
        /* set pageflip to happen anywhere in vblank interval */
        WREG32(EVERGREEN_MASTER_UPDATE_MODE + radeon_crtc->crtc_offset, 0);
 
-       if (!atomic && fb && fb != crtc->primary->fb) {
+       if (fb && fb != crtc->primary->fb) {
                rbo = gem_to_radeon_bo(fb->obj[0]);
                r = radeon_bo_reserve(rbo, false);
                if (unlikely(r != 0))
@@ -1454,7 +1444,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
 
 static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
                                  struct drm_framebuffer *fb,
-                                 int x, int y, int atomic)
+                                 int x, int y)
 {
        struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);
        struct drm_device *dev = crtc->dev;
@@ -1470,15 +1460,12 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
        bool bypass_lut = false;
 
        /* no fb bound */
-       if (!atomic && !crtc->primary->fb) {
+       if (!crtc->primary->fb) {
                DRM_DEBUG_KMS("No FB bound\n");
                return 0;
        }
 
-       if (atomic)
-               target_fb = fb;
-       else
-               target_fb = crtc->primary->fb;
+       target_fb = crtc->primary->fb;
 
        obj = target_fb->obj[0];
        rbo = gem_to_radeon_bo(obj);
@@ -1486,17 +1473,10 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
        if (unlikely(r != 0))
                return r;
 
-       /* If atomic, assume fb object is pinned & idle & fenced and
-        * just update base pointers
-        */
-       if (atomic)
-               fb_location = radeon_bo_gpu_offset(rbo);
-       else {
-               r = radeon_bo_pin(rbo, RADEON_GEM_DOMAIN_VRAM, &fb_location);
-               if (unlikely(r != 0)) {
-                       radeon_bo_unreserve(rbo);
-                       return -EINVAL;
-               }
+       r = radeon_bo_pin(rbo, RADEON_GEM_DOMAIN_VRAM, &fb_location);
+       if (unlikely(r != 0)) {
+               radeon_bo_unreserve(rbo);
+               return -EINVAL;
        }
        radeon_bo_get_tiling_flags(rbo, &tiling_flags, NULL);
        radeon_bo_unreserve(rbo);
@@ -1645,7 +1625,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
        /* set pageflip to happen only at start of vblank interval (front porch) */
        WREG32(AVIVO_D1MODE_MASTER_UPDATE_MODE + radeon_crtc->crtc_offset, 3);
 
-       if (!atomic && fb && fb != crtc->primary->fb) {
+       if (fb && fb != crtc->primary->fb) {
                rbo = gem_to_radeon_bo(fb->obj[0]);
                r = radeon_bo_reserve(rbo, false);
                if (unlikely(r != 0))
@@ -1667,26 +1647,11 @@ int atombios_crtc_set_base(struct drm_crtc *crtc, int x, int y,
        struct radeon_device *rdev = dev->dev_private;
 
        if (ASIC_IS_DCE4(rdev))
-               return dce4_crtc_do_set_base(crtc, old_fb, x, y, 0);
-       else if (ASIC_IS_AVIVO(rdev))
-               return avivo_crtc_do_set_base(crtc, old_fb, x, y, 0);
-       else
-               return radeon_crtc_do_set_base(crtc, old_fb, x, y, 0);
-}
-
-int atombios_crtc_set_base_atomic(struct drm_crtc *crtc,
-                                 struct drm_framebuffer *fb,
-                                 int x, int y, enum mode_set_atomic state)
-{
-       struct drm_device *dev = crtc->dev;
-       struct radeon_device *rdev = dev->dev_private;
-
-       if (ASIC_IS_DCE4(rdev))
-               return dce4_crtc_do_set_base(crtc, fb, x, y, 1);
+               return dce4_crtc_do_set_base(crtc, old_fb, x, y);
        else if (ASIC_IS_AVIVO(rdev))
-               return avivo_crtc_do_set_base(crtc, fb, x, y, 1);
+               return avivo_crtc_do_set_base(crtc, old_fb, x, y);
        else
-               return radeon_crtc_do_set_base(crtc, fb, x, y, 1);
+               return radeon_crtc_do_set_base(crtc, old_fb, x, y);
 }
 
 /* properly set additional regs when using atombios */
@@ -2215,7 +2180,6 @@ static const struct drm_crtc_helper_funcs atombios_helper_funcs = {
        .mode_fixup = atombios_crtc_mode_fixup,
        .mode_set = atombios_crtc_mode_set,
        .mode_set_base = atombios_crtc_set_base,
-       .mode_set_base_atomic = atombios_crtc_set_base_atomic,
        .prepare = atombios_crtc_prepare,
        .commit = atombios_crtc_commit,
        .disable = atombios_crtc_disable,

diff --git a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
index 825b351ff53cc73b3f71c0a1d94e9797e8f0f864..a1054c8094d46eb9ce5ef901aa5d8a0aa7b91efb 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
@@ -360,19 +360,12 @@ static void radeon_crtc_dpms(struct drm_crtc *crtc, int mode)
 int radeon_crtc_set_base(struct drm_crtc *crtc, int x, int y,
                         struct drm_framebuffer *old_fb)
 {
-       return radeon_crtc_do_set_base(crtc, old_fb, x, y, 0);
-}
-
-int radeon_crtc_set_base_atomic(struct drm_crtc *crtc,
-                               struct drm_framebuffer *fb,
-                               int x, int y, enum mode_set_atomic state)
-{
-       return radeon_crtc_do_set_base(crtc, fb, x, y, 1);
+       return radeon_crtc_do_set_base(crtc, old_fb, x, y);
 }
 
 int radeon_crtc_do_set_base(struct drm_crtc *crtc,
                         struct drm_framebuffer *fb,
-                        int x, int y, int atomic)
+                        int x, int y)
 {
        struct drm_device *dev = crtc->dev;
        struct radeon_device *rdev = dev->dev_private;
@@ -390,15 +383,12 @@ int radeon_crtc_do_set_base(struct drm_crtc *crtc,
 
        DRM_DEBUG_KMS("\n");
        /* no fb bound */
-       if (!atomic && !crtc->primary->fb) {
+       if (!crtc->primary->fb) {
                DRM_DEBUG_KMS("No FB bound\n");
                return 0;
        }
 
-       if (atomic)
-               target_fb = fb;
-       else
-               target_fb = crtc->primary->fb;
+       target_fb = crtc->primary->fb;
 
        switch (target_fb->format->cpp[0] * 8) {
        case 8:
@@ -445,7 +435,7 @@ retry:
                 * We don't shutdown the display controller because new buffer
                 * will end up in same spot.
                 */
-               if (!atomic && fb && fb != crtc->primary->fb) {
+               if (fb && fb != crtc->primary->fb) {
                        struct radeon_bo *old_rbo;
                        unsigned long nsize, osize;
 
@@ -555,7 +545,7 @@ retry:
        WREG32(RADEON_CRTC_OFFSET + radeon_crtc->crtc_offset, crtc_offset);
        WREG32(RADEON_CRTC_PITCH + radeon_crtc->crtc_offset, crtc_pitch);
 
-       if (!atomic && fb && fb != crtc->primary->fb) {
+       if (fb && fb != crtc->primary->fb) {
                rbo = gem_to_radeon_bo(fb->obj[0]);
                r = radeon_bo_reserve(rbo, false);
                if (unlikely(r != 0))
@@ -1108,7 +1098,6 @@ static const struct drm_crtc_helper_funcs legacy_helper_funcs = {
        .mode_fixup = radeon_crtc_mode_fixup,
        .mode_set = radeon_crtc_mode_set,
        .mode_set_base = radeon_crtc_set_base,
-       .mode_set_base_atomic = radeon_crtc_set_base_atomic,
        .prepare = radeon_crtc_prepare,
        .commit = radeon_crtc_commit,
        .disable = radeon_crtc_disable,

diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 9e34da2cacef6b8ba23dad02e944839f72277286..088af85902f79e6dfe4438a72beae72a5800803f 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -804,10 +804,6 @@ extern bool radeon_encoder_is_digital(struct drm_encoder *encoder);
 extern void radeon_crtc_load_lut(struct drm_crtc *crtc);
 extern int atombios_crtc_set_base(struct drm_crtc *crtc, int x, int y,
                                   struct drm_framebuffer *old_fb);
-extern int atombios_crtc_set_base_atomic(struct drm_crtc *crtc,
-                                        struct drm_framebuffer *fb,
-                                        int x, int y,
-                                        enum mode_set_atomic state);
 extern int atombios_crtc_mode_set(struct drm_crtc *crtc,
                                   struct drm_display_mode *mode,
                                   struct drm_display_mode *adjusted_mode,
@@ -817,13 +813,9 @@ extern void atombios_crtc_dpms(struct drm_crtc *crtc, int mode);
 
 extern int radeon_crtc_set_base(struct drm_crtc *crtc, int x, int y,
                                 struct drm_framebuffer *old_fb);
-extern int radeon_crtc_set_base_atomic(struct drm_crtc *crtc,
-                                      struct drm_framebuffer *fb,
-                                      int x, int y,
-                                      enum mode_set_atomic state);
 extern int radeon_crtc_do_set_base(struct drm_crtc *crtc,
                                   struct drm_framebuffer *fb,
-                                  int x, int y, int atomic);
+                                  int x, int y);
 extern int radeon_crtc_cursor_set2(struct drm_crtc *crtc,
                                   struct drm_file *file_priv,
                                   uint32_t handle,