Patch: use REQBUFS properly

zbar.spec

@@ -3,7 +3,7 @@
 
 Name:           zbar
 Version:        0.10
-Release:        22%{?dist}
+Release:        23%{?dist}
 Summary:        Bar code reader
 
 Group:          User Interface/X Hardware Support
@@ -13,6 +13,7 @@ Source0:        http://downloads.sourceforge.net/%{name}/%{name}-%{version}.tar.
 Patch0:		zbar_update_to_hg.patch
 Patch1:		zbar_use_libv4l.patch
 Patch2:		zbar_choose_supported_format_first.patch
+Patch3:		zbar_use_REQBUFS_properly.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
  
 BuildRequires:	autoconf automake libtool python-devel gettext-devel
@@ -86,6 +87,7 @@ scanning widget.
 %patch0 -p1
 %patch1 -p1
 %patch2 -p1
+%patch3 -p1
 
 %build
 autoreconf -vfi
@@ -179,6 +181,9 @@ rm -rf $RPM_BUILD_ROOT
 %{_includedir}/zbar/QZBar*.h
 
 %changelog
+* Sat Jun 06 2015 Douglas Schilling Landgraf <dougsland@redhat.com> - 0.10-23
+- Add patch to use REQBUFS properly
+
 * Sat May 02 2015 Kalev Lember <kalevlember@gmail.com> - 0.10-22
 - Rebuilt for GCC 5 C++11 ABI change
 

zbar_use_REQBUFS_properly.patch

@@ -0,0 +1,124 @@
+From a8ed8c04c119e5a323a2c79fcd0d28b4d29fc28a Mon Sep 17 00:00:00 2001
+From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
+Date: Thu, 23 Apr 2015 22:56:09 -0300
+Subject: [PATCH] v4l2: use REQBUFS properly
+
+There are two issues on this driver with regards to buffer
+request:
+
+1) it is not calling VIDIOC_REQBUFS for USERPTR;
+
+2) It is calling VIDIOC_REQBUFS at probe, to check the max
+   number of supported buffers, but it doesn't deallocate
+   the buffers at the end of the probe function.
+
+Fix those issues. Also, improve the error/warning messages
+associated with possible problems.
+
+This is based on the issues detected by the patch proposed
+to fix this bug:
+	https://bugs.archlinux.org/task/44091
+
+Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
+
+diff --git a/zbar/video/v4l2.c b/zbar/video/v4l2.c
+index aabd16643ddc..f6662d3707f9 100644
+--- a/zbar/video/v4l2.c
++++ b/zbar/video/v4l2.c
+@@ -201,21 +201,6 @@ static int v4l2_cleanup (zbar_video_t *vdo)
+ 
+ static int v4l2_mmap_buffers (zbar_video_t *vdo)
+ {
+-    struct v4l2_requestbuffers rb;
+-    memset(&rb, 0, sizeof(rb));
+-    rb.count = vdo->num_images;
+-    rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+-    rb.memory = V4L2_MEMORY_MMAP;
+-    if(v4l2_ioctl(vdo->fd, VIDIOC_REQBUFS, &rb) < 0)
+-        return(err_capture(vdo, SEV_ERROR, ZBAR_ERR_SYSTEM, __func__,
+-                           "requesting video frame buffers (VIDIOC_REQBUFS)"));
+-    zprintf(1, "mapping %u buffers (of %d requested)\n",
+-            rb.count, vdo->num_images);
+-    if(!rb.count)
+-        return(err_capture(vdo, SEV_ERROR, ZBAR_ERR_INVALID, __func__,
+-                           "driver returned 0 buffers"));
+-    if(vdo->num_images > rb.count)
+-        vdo->num_images = rb.count;
+ 
+     struct v4l2_buffer vbuf;
+     memset(&vbuf, 0, sizeof(vbuf));
+@@ -313,8 +298,32 @@ static int v4l2_set_format (zbar_video_t *vdo,
+ static int v4l2_init (zbar_video_t *vdo,
+                       uint32_t fmt)
+ {
++    struct v4l2_requestbuffers rb;
+     if(v4l2_set_format(vdo, fmt))
+         return(-1);
++
++    memset(&rb, 0, sizeof(rb));
++    rb.count = vdo->num_images;
++    rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
++    if(vdo->iomode == VIDEO_MMAP)
++        rb.memory = V4L2_MEMORY_MMAP;
++    else
++        rb.memory = V4L2_MEMORY_USERPTR;
++
++    if(v4l2_ioctl(vdo->fd, VIDIOC_REQBUFS, &rb) < 0)
++        return(err_capture(vdo, SEV_ERROR, ZBAR_ERR_SYSTEM, __func__,
++                           "requesting video frame buffers (VIDIOC_REQBUFS)"));
++
++    if(!rb.count)
++        return(err_capture(vdo, SEV_ERROR, ZBAR_ERR_INVALID, __func__,
++                           "driver returned 0 buffers"));
++
++    if(vdo->num_images > rb.count)
++        vdo->num_images = rb.count;
++
++    zprintf(1, "using %u buffers (of %d requested)\n",
++            rb.count, vdo->num_images);
++
+     if(vdo->iomode == VIDEO_MMAP)
+         return(v4l2_mmap_buffers(vdo));
+     return(0);
+@@ -324,7 +333,7 @@ static int v4l2_probe_iomode (zbar_video_t *vdo)
+ {
+     struct v4l2_requestbuffers rb;
+     memset(&rb, 0, sizeof(rb));
+-    rb.count = vdo->num_images; /* FIXME workaround broken drivers */
++    rb.count = vdo->num_images;
+     rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+     if(vdo->iomode == VIDEO_MMAP)
+         rb.memory = V4L2_MEMORY_MMAP;
+@@ -340,14 +349,31 @@ static int v4l2_probe_iomode (zbar_video_t *vdo)
+             return(err_capture(vdo, SEV_ERROR, ZBAR_ERR_SYSTEM, __func__,
+                                "querying streaming mode (VIDIOC_REQBUFS)"));
+ #ifdef HAVE_SYS_MMAN_H
++	err_capture(vdo, SEV_WARNING, ZBAR_ERR_SYSTEM, __func__,
++                               "USERPTR failed. Falling back to mmap");
+         vdo->iomode = VIDEO_MMAP;
++#else
++	return err_capture(vdo, SEV_ERROR, ZBAR_ERR_SYSTEM, __func__,
++                           "Userptr not supported, and zbar was compiled without mmap support"));
+ #endif
+     }
+     else {
+         if(!vdo->iomode)
+-            vdo->iomode = VIDEO_USERPTR;
++            rb.memory = V4L2_MEMORY_USERPTR;
++	/* Update the num_images with the max supported by the driver */
+         if(rb.count)
+             vdo->num_images = rb.count;
++	else
++            err_capture(vdo, SEV_WARNING, ZBAR_ERR_SYSTEM, __func__,
++                        "Something is wrong: number of buffers returned by REQBUF is zero!");
++
++        /* requesting 0 buffers
++         * This cleans up the buffers allocated previously on probe
++         */
++	rb.count = 0;
++        if(v4l2_ioctl(vdo->fd, VIDIOC_REQBUFS, &rb) < 0)
++            err_capture(vdo, SEV_WARNING, ZBAR_ERR_SYSTEM, __func__,
++                        "releasing video frame buffers (VIDIOC_REQBUFS)");
+     }
+     return(0);
+ }