cx25821: sanitize cx25821_get_audio_data() a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 25 insertions, 58 deletions

diff --git a/drivers/media/pci/cx25821/cx25821-audio-upstream.c b/drivers/media/pci/cx25821/cx25821-audio-upstream.c
index 87491ca05ee5..d930f308e94e 100644
--- a/drivers/media/pci/cx25821/cx25821-audio-upstream.c
+++ b/drivers/media/pci/cx25821/cx25821-audio-upstream.c
@@ -259,79 +259,46 @@ void cx25821_free_mem_upstream_audio(struct cx25821_dev *dev)
 static int cx25821_get_audio_data(struct cx25821_dev *dev,
                            struct sram_channel *sram_ch)
 {
-        struct file *myfile;
+        struct file *file;
         int frame_index_temp = dev->_audioframe_index;
         int i = 0;
-        int line_size = AUDIO_LINE_SIZE;
         int frame_size = AUDIO_DATA_BUF_SZ;
         int frame_offset = frame_size * frame_index_temp;
-        ssize_t vfs_read_retval = 0;
-        char mybuf[line_size];
+        char mybuf[AUDIO_LINE_SIZE];
         loff_t file_offset = dev->_audioframe_count * frame_size;
-        loff_t pos;
-        mm_segment_t old_fs;
+        char *p = NULL;
 
         if (dev->_audiofile_status == END_OF_FILE)
                 return 0;
 
-        myfile = filp_open(dev->_audiofilename, O_RDONLY | O_LARGEFILE, 0);
+        file = filp_open(dev->_audiofilename, O_RDONLY | O_LARGEFILE, 0);
+        if (IS_ERR(file)) {
+                pr_err("%s(): ERROR opening file(%s) with errno = %ld!\n",
+                       __func__, dev->_audiofilename, -PTR_ERR(file));
+                return PTR_ERR(file);
+        }
 
-        if (IS_ERR(myfile)) {
-                const int open_errno = -PTR_ERR(myfile);
-                pr_err("%s(): ERROR opening file(%s) with errno = %d!\n",
-                       __func__, dev->_audiofilename, open_errno);
-                return PTR_ERR(myfile);
-        } else {
-                if (!(myfile->f_op)) {
-                        pr_err("%s(): File has no file operations registered!\n",
-                                __func__);
-                        filp_close(myfile, NULL);
-                        return -EIO;
-                }
+        if (dev->_audiodata_buf_virt_addr)
+                p = (char *)dev->_audiodata_buf_virt_addr + frame_offset;
 
-                if (!myfile->f_op->read) {
-                        pr_err("%s(): File has no READ operations registered!\n",
+        for (i = 0; i < dev->_audio_lines_count; i++) {
+                int n = kernel_read(file, file_offset, mybuf, AUDIO_LINE_SIZE);
+                if (n < AUDIO_LINE_SIZE) {
+                        pr_info("Done: exit %s() since no more bytes to read from Audio file\n",
                                 __func__);
-                        filp_close(myfile, NULL);
-                        return -EIO;
+                        dev->_audiofile_status = END_OF_FILE;
+                        fput(file);
+                        return 0;
                 }
-
-                pos = myfile->f_pos;
-                old_fs = get_fs();
-                set_fs(KERNEL_DS);
-
-                for (i = 0; i < dev->_audio_lines_count; i++) {
-                        pos = file_offset;
-
-                        vfs_read_retval = vfs_read(myfile, mybuf, line_size,
-                                                                        &pos);
-
-                        if (vfs_read_retval > 0 && vfs_read_retval == line_size
-                            && dev->_audiodata_buf_virt_addr != NULL) {
-                                memcpy((void *)(dev->_audiodata_buf_virt_addr +
-                                                frame_offset / 4), mybuf,
-                                        vfs_read_retval);
-                        }
-
-                        file_offset += vfs_read_retval;
-                        frame_offset += vfs_read_retval;
-
-                        if (vfs_read_retval < line_size) {
-                                pr_info("Done: exit %s() since no more bytes to read from Audio file\n",
-                                        __func__);
-                                break;
-                        }
+                dev->_audiofile_status = IN_PROGRESS;
+                if (p) {
+                        memcpy(p, mybuf, n);
+                        p += n;
                 }
-
-                if (i > 0)
-                        dev->_audioframe_count++;
-
-                dev->_audiofile_status = (vfs_read_retval == line_size) ?
-                                                IN_PROGRESS : END_OF_FILE;
-
-                set_fs(old_fs);
-                filp_close(myfile, NULL);
+                file_offset += n;
         }
+        dev->_audioframe_count++;
+        fput(file);
 
         return 0;
 }