[igt-dev] [PATCH v2 5/8] tests/fbdev: Add tests for write operations on framebuffer

[Thomas Zimmermann]

The write tests check the written buffer against the content of the mapped
framebuffer.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 tests/fbdev.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/fbdev.c b/tests/fbdev.c
index 48ffbbf5..f40a9ee1 100644
--- a/tests/fbdev.c
+++ b/tests/fbdev.c
@@ -138,6 +138,27 @@ static void framebuffer_tests(int fd)
 		igt_require_f(pos, "found 0x55 at pos %zu, none expected\n", pos - buf);
 	}
 
+	igt_subtest("write") {
+		ssize_t ret;
+		int cmp;
+
+		igt_describe("Check write operations on framebuffer memory");
+
+		/* write 0 to framebuffer and compare */
+		memset(buf, 0, fix_info.smem_len);
+		ret = pwrite(fd, buf, fix_info.smem_len, 0);
+		igt_require_f(ret == (ssize_t)fix_info.smem_len, "pwrite failed, ret=%zd\n", ret);
+		cmp = memcmp(map, buf, fix_info.smem_len);
+		igt_require_f(!cmp, "write buffer differs from mapped framebuffer for 0\n");
+
+		/* write 0x55 to framebuffer and compare */
+		memset(buf, 0x55, fix_info.smem_len);
+		ret = pwrite(fd, buf, fix_info.smem_len, 0);
+		igt_require_f(ret == (ssize_t)fix_info.smem_len, "pwrite failed, ret=%zd\n", ret);
+		cmp = memcmp(map, buf, fix_info.smem_len);
+		igt_require_f(!cmp, "write buffer differs from mapped framebuffer for 0\n");
+	}
+
 	igt_fixture {
 		free(buf);
 		memset(map, 0, fix_info.smem_len); // don't leave garbage on the screen
-- 
2.29.0