Commit a22461ed authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

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 9c79e0b1 ("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: default avatarThomas Zimmermann <tzimmermann@suse.de>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarSimona Vetter <simona.vetter@ffwll.ch>
Acked-by: default avatarDaniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20251125130634.1080966-4-tzimmermann@suse.de
parent 046a10f4

drivers/gpu/drm/radeon/atombios_crtc.c

+19 −55
Original line number Diff line number Diff line
@@ -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;
@@ -1150,34 +1150,24 @@ 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;



	/* 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;

	}

	}



	radeon_bo_get_tiling_flags(rbo, &tiling_flags, NULL);

	radeon_bo_unreserve(rbo);
@@ -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;
@@ -1470,14 +1460,11 @@ 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;



	obj = target_fb->obj[0];
@@ -1486,18 +1473,11 @@ 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;

	}

	}

	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,

drivers/gpu/drm/radeon/radeon_legacy_crtc.c

+6 −17
Original line number Diff line number Diff line
@@ -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;
@@ -390,14 +383,11 @@ 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;



	switch (target_fb->format->cpp[0] * 8) {
@@ -445,7 +435,7 @@ int radeon_crtc_do_set_base(struct drm_crtc *crtc, 
		 * 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 @@ int radeon_crtc_do_set_base(struct drm_crtc *crtc, 
	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,

drivers/gpu/drm/radeon/radeon_mode.h

+1 −9
Original line number Diff line number Diff line
@@ -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,