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* [PATCH 0/2] A couple drm/msm fixes
@ 2020-09-01 21:59 Stephen Boyd
  2020-09-01 21:59 ` [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() Stephen Boyd
  2020-09-01 21:59 ` [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds() Stephen Boyd
  0 siblings, 2 replies; 6+ messages in thread
From: Stephen Boyd @ 2020-09-01 21:59 UTC (permalink / raw)
  To: Rob Clark; +Cc: linux-kernel, linux-arm-msm, freedreno, dri-devel, Sean Paul

Two small fixes for an UBSAN warning and to make debugging a little
easier.

Stephen Boyd (2):
  drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check()
  drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds()

 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

-- 
Sent by a computer, using git, on the internet


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check()
  2020-09-01 21:59 [PATCH 0/2] A couple drm/msm fixes Stephen Boyd
@ 2020-09-01 21:59 ` Stephen Boyd
  2020-09-01 22:05   ` abhinavk
  2020-09-02  7:05   ` Sai Prakash Ranjan
  2020-09-01 21:59 ` [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds() Stephen Boyd
  1 sibling, 2 replies; 6+ messages in thread
From: Stephen Boyd @ 2020-09-01 21:59 UTC (permalink / raw)
  To: Rob Clark
  Cc: linux-kernel, linux-arm-msm, freedreno, dri-devel, Sean Paul,
	Abhinav Kumar, Jeykumar Sankaran, Jordan Crouse, Sean Paul

The cstate->num_mixers member is only set to a non-zero value once
dpu_encoder_virt_mode_set() is called, but the atomic check function can
be called by userspace before that. Let's avoid the div-by-zero here and
inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic
check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes
an UBSAN warning:

 UBSAN: Undefined behaviour in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31
 division by zero
 CPU: 7 PID: 409 Comm: frecon Tainted: G S                5.4.31 #128
 Hardware name: Google Trogdor (rev0) (DT)
 Call trace:
  dump_backtrace+0x0/0x14c
  show_stack+0x20/0x2c
  dump_stack+0xa0/0xd8
  __ubsan_handle_divrem_overflow+0xec/0x110
  dpu_crtc_atomic_check+0x97c/0x9d4
  drm_atomic_helper_check_planes+0x160/0x1c8
  drm_atomic_helper_check+0x54/0xbc
  drm_atomic_check_only+0x6a8/0x880
  drm_atomic_commit+0x20/0x5c
  drm_atomic_helper_set_config+0x98/0xa0
  drm_mode_setcrtc+0x308/0x5dc
  drm_ioctl_kernel+0x9c/0x114
  drm_ioctl+0x2ac/0x4b0
  drm_compat_ioctl+0xe8/0x13c
  __arm64_compat_sys_ioctl+0x184/0x324
  el0_svc_common+0xa4/0x154
  el0_svc_compat_handler+0x

Cc: Abhinav Kumar <abhinavk@codeaurora.org>
Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index f272a8d0f95b..74294b5ed93f 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -881,7 +881,7 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
 	struct drm_plane *plane;
 	struct drm_display_mode *mode;
 
-	int cnt = 0, rc = 0, mixer_width, i, z_pos;
+	int cnt = 0, rc = 0, mixer_width = 0, i, z_pos;
 
 	struct dpu_multirect_plane_states multirect_plane[DPU_STAGE_MAX * 2];
 	int multirect_count = 0;
@@ -914,9 +914,11 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
 
 	memset(pipe_staged, 0, sizeof(pipe_staged));
 
-	mixer_width = mode->hdisplay / cstate->num_mixers;
+	if (cstate->num_mixers) {
+		mixer_width = mode->hdisplay / cstate->num_mixers;
 
-	_dpu_crtc_setup_lm_bounds(crtc, state);
+		_dpu_crtc_setup_lm_bounds(crtc, state);
+	}
 
 	crtc_rect.x2 = mode->hdisplay;
 	crtc_rect.y2 = mode->vdisplay;
-- 
Sent by a computer, using git, on the internet


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds()
  2020-09-01 21:59 [PATCH 0/2] A couple drm/msm fixes Stephen Boyd
  2020-09-01 21:59 ` [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() Stephen Boyd
@ 2020-09-01 21:59 ` Stephen Boyd
  2020-09-01 22:06   ` abhinavk
  1 sibling, 1 reply; 6+ messages in thread
From: Stephen Boyd @ 2020-09-01 21:59 UTC (permalink / raw)
  To: Rob Clark
  Cc: linux-kernel, linux-arm-msm, freedreno, dri-devel, Sean Paul,
	Abhinav Kumar, Jeykumar Sankaran, Jordan Crouse, Sean Paul

This function is called quite often if you have a blinking cursor on the
screen, hello page flip. Let's drop this debug print here because it
means enabling the print via the module parameter starts to spam the
debug console.

Cc: Abhinav Kumar <abhinavk@codeaurora.org>
Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 74294b5ed93f..2966e488bfd0 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -421,8 +421,6 @@ static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,
 
 		trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r);
 	}
-
-	drm_mode_debug_printmodeline(adj_mode);
 }
 
 static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_state *state,
-- 
Sent by a computer, using git, on the internet


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check()
  2020-09-01 21:59 ` [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() Stephen Boyd
@ 2020-09-01 22:05   ` abhinavk
  2020-09-02  7:05   ` Sai Prakash Ranjan
  1 sibling, 0 replies; 6+ messages in thread
From: abhinavk @ 2020-09-01 22:05 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Rob Clark, linux-kernel, linux-arm-msm, freedreno, dri-devel,
	Sean Paul, Jeykumar Sankaran, Jordan Crouse, Sean Paul,
	linux-arm-msm-owner

On 2020-09-01 14:59, Stephen Boyd wrote:
> The cstate->num_mixers member is only set to a non-zero value once
> dpu_encoder_virt_mode_set() is called, but the atomic check function 
> can
> be called by userspace before that. Let's avoid the div-by-zero here 
> and
> inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic
> check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes
> an UBSAN warning:
> 
>  UBSAN: Undefined behaviour in 
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31
>  division by zero
>  CPU: 7 PID: 409 Comm: frecon Tainted: G S                5.4.31 #128
>  Hardware name: Google Trogdor (rev0) (DT)
>  Call trace:
>   dump_backtrace+0x0/0x14c
>   show_stack+0x20/0x2c
>   dump_stack+0xa0/0xd8
>   __ubsan_handle_divrem_overflow+0xec/0x110
>   dpu_crtc_atomic_check+0x97c/0x9d4
>   drm_atomic_helper_check_planes+0x160/0x1c8
>   drm_atomic_helper_check+0x54/0xbc
>   drm_atomic_check_only+0x6a8/0x880
>   drm_atomic_commit+0x20/0x5c
>   drm_atomic_helper_set_config+0x98/0xa0
>   drm_mode_setcrtc+0x308/0x5dc
>   drm_ioctl_kernel+0x9c/0x114
>   drm_ioctl+0x2ac/0x4b0
>   drm_compat_ioctl+0xe8/0x13c
>   __arm64_compat_sys_ioctl+0x184/0x324
>   el0_svc_common+0xa4/0x154
>   el0_svc_compat_handler+0x
> 
> Cc: Abhinav Kumar <abhinavk@codeaurora.org>
> Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
> Cc: Jordan Crouse <jcrouse@codeaurora.org>
> Cc: Sean Paul <seanpaul@chromium.org>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index f272a8d0f95b..74294b5ed93f 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -881,7 +881,7 @@ static int dpu_crtc_atomic_check(struct drm_crtc 
> *crtc,
>  	struct drm_plane *plane;
>  	struct drm_display_mode *mode;
> 
> -	int cnt = 0, rc = 0, mixer_width, i, z_pos;
> +	int cnt = 0, rc = 0, mixer_width = 0, i, z_pos;
> 
>  	struct dpu_multirect_plane_states multirect_plane[DPU_STAGE_MAX * 2];
>  	int multirect_count = 0;
> @@ -914,9 +914,11 @@ static int dpu_crtc_atomic_check(struct drm_crtc 
> *crtc,
> 
>  	memset(pipe_staged, 0, sizeof(pipe_staged));
> 
> -	mixer_width = mode->hdisplay / cstate->num_mixers;
> +	if (cstate->num_mixers) {
> +		mixer_width = mode->hdisplay / cstate->num_mixers;
> 
> -	_dpu_crtc_setup_lm_bounds(crtc, state);
> +		_dpu_crtc_setup_lm_bounds(crtc, state);
> +	}
> 
>  	crtc_rect.x2 = mode->hdisplay;
>  	crtc_rect.y2 = mode->vdisplay;

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds()
  2020-09-01 21:59 ` [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds() Stephen Boyd
@ 2020-09-01 22:06   ` abhinavk
  0 siblings, 0 replies; 6+ messages in thread
From: abhinavk @ 2020-09-01 22:06 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Rob Clark, linux-kernel, linux-arm-msm, freedreno, dri-devel,
	Sean Paul, Jeykumar Sankaran, Jordan Crouse, Sean Paul,
	linux-arm-msm-owner

On 2020-09-01 14:59, Stephen Boyd wrote:
> This function is called quite often if you have a blinking cursor on 
> the
> screen, hello page flip. Let's drop this debug print here because it
> means enabling the print via the module parameter starts to spam the
> debug console.
> 
> Cc: Abhinav Kumar <abhinavk@codeaurora.org>
> Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
> Cc: Jordan Crouse <jcrouse@codeaurora.org>
> Cc: Sean Paul <seanpaul@chromium.org>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 74294b5ed93f..2966e488bfd0 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -421,8 +421,6 @@ static void _dpu_crtc_setup_lm_bounds(struct 
> drm_crtc *crtc,
> 
>  		trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r);
>  	}
> -
> -	drm_mode_debug_printmodeline(adj_mode);
>  }
> 
>  static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_state *state,

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check()
  2020-09-01 21:59 ` [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() Stephen Boyd
  2020-09-01 22:05   ` abhinavk
@ 2020-09-02  7:05   ` Sai Prakash Ranjan
  1 sibling, 0 replies; 6+ messages in thread
From: Sai Prakash Ranjan @ 2020-09-02  7:05 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Rob Clark, linux-kernel, linux-arm-msm, freedreno, dri-devel,
	Sean Paul, Abhinav Kumar, Jeykumar Sankaran, Jordan Crouse,
	Sean Paul, linux-arm-msm-owner

On 2020-09-02 03:29, Stephen Boyd wrote:
> The cstate->num_mixers member is only set to a non-zero value once
> dpu_encoder_virt_mode_set() is called, but the atomic check function 
> can
> be called by userspace before that. Let's avoid the div-by-zero here 
> and
> inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic
> check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes
> an UBSAN warning:
> 
>  UBSAN: Undefined behaviour in 
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31
>  division by zero
>  CPU: 7 PID: 409 Comm: frecon Tainted: G S                5.4.31 #128
>  Hardware name: Google Trogdor (rev0) (DT)
>  Call trace:
>   dump_backtrace+0x0/0x14c
>   show_stack+0x20/0x2c
>   dump_stack+0xa0/0xd8
>   __ubsan_handle_divrem_overflow+0xec/0x110
>   dpu_crtc_atomic_check+0x97c/0x9d4
>   drm_atomic_helper_check_planes+0x160/0x1c8
>   drm_atomic_helper_check+0x54/0xbc
>   drm_atomic_check_only+0x6a8/0x880
>   drm_atomic_commit+0x20/0x5c
>   drm_atomic_helper_set_config+0x98/0xa0
>   drm_mode_setcrtc+0x308/0x5dc
>   drm_ioctl_kernel+0x9c/0x114
>   drm_ioctl+0x2ac/0x4b0
>   drm_compat_ioctl+0xe8/0x13c
>   __arm64_compat_sys_ioctl+0x184/0x324
>   el0_svc_common+0xa4/0x154
>   el0_svc_compat_handler+0x
> 
> Cc: Abhinav Kumar <abhinavk@codeaurora.org>
> Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
> Cc: Jordan Crouse <jcrouse@codeaurora.org>
> Cc: Sean Paul <seanpaul@chromium.org>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---

Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a 
member
of Code Aurora Forum, hosted by The Linux Foundation

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-09-02  7:05 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-01 21:59 [PATCH 0/2] A couple drm/msm fixes Stephen Boyd
2020-09-01 21:59 ` [PATCH 1/2] drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() Stephen Boyd
2020-09-01 22:05   ` abhinavk
2020-09-02  7:05   ` Sai Prakash Ranjan
2020-09-01 21:59 ` [PATCH 2/2] drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds() Stephen Boyd
2020-09-01 22:06   ` abhinavk

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