[media] Fix mmap() example in the V4L2 API DocBook

Correct ioctl return value handling and fix coding style issues. [mchehab@redhat.com: return -1 is OK, according with ioctl manpages. Reverting ioctl changes] Signed-off-by: Pawel Osciak <pawel@osciak.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] Fix mmap() example in the V4L2 API DocBook
Correct ioctl return value handling and fix coding style issues. [mchehab@redhat.com: return -1 is OK, according with ioctl manpages. Reverting ioctl changes] Signed-off-by: Pawel Osciak <pawel@osciak.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Pawel Osciak · Mauro Carvalho Chehab
1 parent 08b99e26a3
Showing 1 changed file with 18 additions and 18 deletions Side-by-side Diff
Documentation/DocBook/v4l/io.xml
@@ -141,63 +141,63 @@
 } *buffers;
 unsigned int i;
  
-memset (&amp;reqbuf, 0, sizeof (reqbuf));
+memset(&amp;reqbuf, 0, sizeof(reqbuf));
 reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 reqbuf.memory = V4L2_MEMORY_MMAP;
 reqbuf.count = 20;
  
 if (-1 == ioctl (fd, &VIDIOC-REQBUFS;, &amp;reqbuf)) {
 	if (errno == EINVAL)
-		printf ("Video capturing or mmap-streaming is not supported\n");
+		printf("Video capturing or mmap-streaming is not supported\n");
 	else
-		perror ("VIDIOC_REQBUFS");
+		perror("VIDIOC_REQBUFS");
  
-	exit (EXIT_FAILURE);
+	exit(EXIT_FAILURE);
 }
  
 /* We want at least five buffers. */
  
 if (reqbuf.count &lt; 5) {
 	/* You may need to free the buffers here. */
-	printf ("Not enough buffer memory\n");
-	exit (EXIT_FAILURE);
+	printf("Not enough buffer memory\n");
+	exit(EXIT_FAILURE);
 }
  
-buffers = calloc (reqbuf.count, sizeof (*buffers));
-assert (buffers != NULL);
+buffers = calloc(reqbuf.count, sizeof(*buffers));
+assert(buffers != NULL);
  
 for (i = 0; i &lt; reqbuf.count; i++) {
 	&v4l2-buffer; buffer;
  
-	memset (&amp;buffer, 0, sizeof (buffer));
+	memset(&amp;buffer, 0, sizeof(buffer));
 	buffer.type = reqbuf.type;
 	buffer.memory = V4L2_MEMORY_MMAP;
 	buffer.index = i;
  
 	if (-1 == ioctl (fd, &VIDIOC-QUERYBUF;, &amp;buffer)) {
-		perror ("VIDIOC_QUERYBUF");
-		exit (EXIT_FAILURE);
+		perror("VIDIOC_QUERYBUF");
+		exit(EXIT_FAILURE);
 	}
  
 	buffers[i].length = buffer.length; /* remember for munmap() */
  
-	buffers[i].start = mmap (NULL, buffer.length,
-				 PROT_READ | PROT_WRITE, /* recommended */
-				 MAP_SHARED,             /* recommended */
-				 fd, buffer.m.offset);
+	buffers[i].start = mmap(NULL, buffer.length,
+				PROT_READ | PROT_WRITE, /* recommended */
+				MAP_SHARED,             /* recommended */
+				fd, buffer.m.offset);
  
 	if (MAP_FAILED == buffers[i].start) {
 		/* If you do not exit here you should unmap() and free()
 		   the buffers mapped so far. */
-		perror ("mmap");
-		exit (EXIT_FAILURE);
+		perror("mmap");
+		exit(EXIT_FAILURE);
 	}
 }
  
 /* Cleanup. */
  
 for (i = 0; i &lt; reqbuf.count; i++)
-	munmap (buffers[i].start, buffers[i].length);
+	munmap(buffers[i].start, buffers[i].length);
       </programlisting>
     </example>
...	...	@@ -141,63 +141,63 @@
141	141	} *buffers;
142	142	unsigned int i;
143	143
144		-memset (&reqbuf, 0, sizeof (reqbuf));
	144	+memset(&reqbuf, 0, sizeof(reqbuf));
145	145	reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
146	146	reqbuf.memory = V4L2_MEMORY_MMAP;
147	147	reqbuf.count = 20;
148	148
149	149	if (-1 == ioctl (fd, &VIDIOC-REQBUFS;, &reqbuf)) {
150	150	if (errno == EINVAL)
151		- printf ("Video capturing or mmap-streaming is not supported\n");
	151	+ printf("Video capturing or mmap-streaming is not supported\n");
152	152	else
153		- perror ("VIDIOC_REQBUFS");
	153	+ perror("VIDIOC_REQBUFS");
154	154
155		- exit (EXIT_FAILURE);
	155	+ exit(EXIT_FAILURE);
156	156	}
157	157
158	158	/* We want at least five buffers. */
159	159
160	160	if (reqbuf.count < 5) {
161	161	/* You may need to free the buffers here. */
162		- printf ("Not enough buffer memory\n");
163		- exit (EXIT_FAILURE);
	162	+ printf("Not enough buffer memory\n");
	163	+ exit(EXIT_FAILURE);
164	164	}
165	165
166		-buffers = calloc (reqbuf.count, sizeof (*buffers));
167		-assert (buffers != NULL);
	166	+buffers = calloc(reqbuf.count, sizeof(*buffers));
	167	+assert(buffers != NULL);
168	168
169	169	for (i = 0; i < reqbuf.count; i++) {
170	170	&v4l2-buffer; buffer;
171	171
172		- memset (&buffer, 0, sizeof (buffer));
	172	+ memset(&buffer, 0, sizeof(buffer));
173	173	buffer.type = reqbuf.type;
174	174	buffer.memory = V4L2_MEMORY_MMAP;
175	175	buffer.index = i;
176	176
177	177	if (-1 == ioctl (fd, &VIDIOC-QUERYBUF;, &buffer)) {
178		- perror ("VIDIOC_QUERYBUF");
179		- exit (EXIT_FAILURE);
	178	+ perror("VIDIOC_QUERYBUF");
	179	+ exit(EXIT_FAILURE);
180	180	}
181	181
182	182	buffers[i].length = buffer.length; /* remember for munmap() */
183	183
184		- buffers[i].start = mmap (NULL, buffer.length,
185		- PROT_READ \| PROT_WRITE, /* recommended */
186		- MAP_SHARED, /* recommended */
187		- fd, buffer.m.offset);
	184	+ buffers[i].start = mmap(NULL, buffer.length,
	185	+ PROT_READ \| PROT_WRITE, /* recommended */
	186	+ MAP_SHARED, /* recommended */
	187	+ fd, buffer.m.offset);
188	188
189	189	if (MAP_FAILED == buffers[i].start) {
190	190	/* If you do not exit here you should unmap() and free()
191	191	the buffers mapped so far. */
192		- perror ("mmap");
193		- exit (EXIT_FAILURE);
	192	+ perror("mmap");
	193	+ exit(EXIT_FAILURE);
194	194	}
195	195	}
196	196
197	197	/* Cleanup. */
198	198
199	199	for (i = 0; i < reqbuf.count; i++)
200		- munmap (buffers[i].start, buffers[i].length);
	200	+ munmap(buffers[i].start, buffers[i].length);
201	201	</programlisting>
202	202	</example>
203	203