On 08/05/2015 04:08 AM, Daniel Vetter wrote: > On Tue, Aug 04, 2015 at 06:30:25PM -0300, Tiago Vignatti wrote: > Nah they don't have to be equal since the problem isn't that nothing goes > out to memory where the display can see it, but usually only parts of it. > I.e. you need to change your test to > - draw black screen (it starts that way so nothing to do really), grab crtc > - draw white screen and make sure you flush correctly, don't bother with > crc (we can't test for inequality > because collisions are too easy) > - draw black screen again without flushing, grab crc > > Then assert that your two crc will be inequal (which they shouldn't be > because some cachelines will still be stuck). Maybe also add a delay > somewhere so you can see the cacheline dirt pattern, it's very > characteristic.
Cool, I've got it now. The test below makes the cachelines dirt, requiring them to get flushed correctly -- I'll work on it now. Should we add that kind of test somewhere in igt BTW? PS: I had an issue with the original kms_pwrite_crc which returns frequent fails. Paulo helped though and showed me that pwrite is currently broken: https://bugs.freedesktop.org/show_bug.cgi?id=86422 Tiago diff --git a/tests/kms_pwrite_crc.c b/tests/kms_pwrite_crc.c index 05b9e38..419b46d 100644 --- a/tests/kms_pwrite_crc.c +++ b/tests/kms_pwrite_crc.c @@ -50,6 +50,20 @@ typedef struct { uint32_t devid; } data_t; +static char *dmabuf_mmap_framebuffer(int drm_fd, struct igt_fb *fb) +{ + int dma_buf_fd; + char *ptr = NULL; + + dma_buf_fd = prime_handle_to_fd(drm_fd, fb->gem_handle); + igt_assert(errno == 0); + + ptr = mmap(NULL, fb->size, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf_fd, 0); + igt_assert(ptr != MAP_FAILED); + + return ptr; +} + static void test(data_t *data) { igt_display_t *display = &data->display; @@ -57,6 +71,7 @@ static void test(data_t *data) struct igt_fb *fb = &data->fb[1]; drmModeModeInfo *mode; cairo_t *cr; + char *ptr; uint32_t caching; void *buf; igt_crc_t crc; @@ -67,6 +82,8 @@ static void test(data_t *data) igt_create_fb(data->drm_fd, mode->hdisplay, mode->vdisplay, DRM_FORMAT_XRGB8888, LOCAL_DRM_FORMAT_MOD_NONE, fb); + ptr = dmabuf_mmap_framebuffer(data->drm_fd, fb); + cr = igt_get_cairo_ctx(data->drm_fd, fb); igt_paint_test_pattern(cr, fb->width, fb->height); cairo_destroy(cr); @@ -83,11 +100,11 @@ static void test(data_t *data) caching = gem_get_caching(data->drm_fd, fb->gem_handle); igt_assert(caching == I915_CACHING_NONE || caching == I915_CACHING_DISPLAY); - /* use pwrite to make the other fb all white too */ + /* use dmabuf pointer to make the other fb all white too */ buf = malloc(fb->size); igt_assert(buf != NULL); memset(buf, 0xff, fb->size); - gem_write(data->drm_fd, fb->gem_handle, 0, buf, fb->size); + memcpy(ptr, buf, fb->size); free(buf); /* and flip to it */