On Wed, 22 Oct 2025, Ville Syrjälä <[email protected]> wrote:
> On Wed, Oct 22, 2025 at 07:10:54PM +0300, Jani Nikula wrote:
>> For reasons still unknown, xe appears to require a stride alignment of
>> XE_PAGE_SIZE, and using 64 leads to sporadic failures. Go back to having
>> separate stride alignment for i915 and xe, until the issue is root
>> caused.
>>
>> v2: Add FIXME comment, reference issue with Link (Ville)
>>
>> Cc: Ville Syrjälä <[email protected]>
>> Cc: Jouni Högander <[email protected]>
>> Cc: Maarten Lankhorst <[email protected]>
>> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6220
>> Fixes: 4a36b339a14a ("drm/xe/fbdev: use the same 64-byte stride alignment as
>> i915")
>> Link:
>> https://lore.kernel.org/r/ae51d1e224048bdc87bf7a56d8f5ebd0fbb6a383.1756931441.git.jani.nik...@intel.com
>> Signed-off-by: Jani Nikula <[email protected]>
>
> Reviewed-by: Ville Syrjälä <[email protected]>
Thanks, pushed.
Now Someone(tm) only needs to get at the bottom of this.
BR,
Jani.
>
>> ---
>> drivers/gpu/drm/i915/display/intel_fbdev.c | 2 +-
>> drivers/gpu/drm/i915/display/intel_fbdev_fb.c | 5 +++++
>> drivers/gpu/drm/i915/display/intel_fbdev_fb.h | 3 +++
>> drivers/gpu/drm/xe/display/intel_fbdev_fb.c | 11 +++++++++++
>> 4 files changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c
>> b/drivers/gpu/drm/i915/display/intel_fbdev.c
>> index 51d3d87caf43..d5c001761aa0 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
>> @@ -218,7 +218,7 @@ static void intel_fbdev_fill_mode_cmd(struct
>> drm_fb_helper_surface_size *sizes,
>> mode_cmd->width = sizes->surface_width;
>> mode_cmd->height = sizes->surface_height;
>>
>> - mode_cmd->pitches[0] = ALIGN(mode_cmd->width *
>> DIV_ROUND_UP(sizes->surface_bpp, 8), 64);
>> + mode_cmd->pitches[0] = intel_fbdev_fb_pitch_align(mode_cmd->width *
>> DIV_ROUND_UP(sizes->surface_bpp, 8));
>> mode_cmd->pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
>>
>> sizes->surface_depth);
>> mode_cmd->modifier[0] = DRM_FORMAT_MOD_LINEAR;
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
>> b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
>> index 56b145841473..0838fdd37254 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
>> @@ -10,6 +10,11 @@
>> #include "i915_drv.h"
>> #include "intel_fbdev_fb.h"
>>
>> +u32 intel_fbdev_fb_pitch_align(u32 stride)
>> +{
>> + return ALIGN(stride, 64);
>> +}
>> +
>> struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int
>> size)
>> {
>> struct drm_i915_private *dev_priv = to_i915(drm);
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
>> b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
>> index 1fa44ed28543..fd0b3775dc1f 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
>> +++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
>> @@ -6,12 +6,15 @@
>> #ifndef __INTEL_FBDEV_FB_H__
>> #define __INTEL_FBDEV_FB_H__
>>
>> +#include <linux/types.h>
>> +
>> struct drm_device;
>> struct drm_gem_object;
>> struct drm_mode_fb_cmd2;
>> struct fb_info;
>> struct i915_vma;
>>
>> +u32 intel_fbdev_fb_pitch_align(u32 stride);
>> struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int
>> size);
>> void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj);
>> int intel_fbdev_fb_fill_info(struct drm_device *drm, struct fb_info *info,
>> diff --git a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
>> b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
>> index af72f7305e5a..7ad76022cb14 100644
>> --- a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
>> +++ b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
>> @@ -12,6 +12,17 @@
>>
>> #include <generated/xe_device_wa_oob.h>
>>
>> +/*
>> + * FIXME: There shouldn't be any reason to have XE_PAGE_SIZE stride
>> + * alignment. The same 64 as i915 uses should be fine, and we shouldn't
>> need to
>> + * have driver specific values. However, dropping the stride alignment to 64
>> + * leads to underflowing the bo pin count in the atomic cleanup work.
>> + */
>> +u32 intel_fbdev_fb_pitch_align(u32 stride)
>> +{
>> + return ALIGN(stride, XE_PAGE_SIZE);
>> +}
>> +
>> struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int
>> size)
>> {
>> struct xe_device *xe = to_xe_device(drm);
>> --
>> 2.47.3
--
Jani Nikula, Intel
