V4L/DVB (9163): ivtvfb: fix sparse warnings and improve write function

Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 37 insertions, 39 deletions

diff --git a/drivers/media/video/ivtv/ivtvfb.c b/drivers/media/video/ivtv/ivtvfb.c
index bdfda48e56bf..249758e53f5f 100644
--- a/drivers/media/video/ivtv/ivtvfb.c
+++ b/drivers/media/video/ivtv/ivtvfb.c
@@ -275,7 +275,6 @@ static int ivtvfb_prep_dec_dma_to_device(struct ivtv *itv,
                                   int size_in_bytes)
 {
         DEFINE_WAIT(wait);
-        int ret = 0;
         int got_sig = 0;
 
         mutex_lock(&itv->udma.lock);
@@ -316,7 +315,7 @@ static int ivtvfb_prep_dec_dma_to_device(struct ivtv *itv,
                 return -EINTR;
         }
 
-        return ret;
+        return 0;
 }
 
 static int ivtvfb_prep_frame(struct ivtv *itv, int cmd, void __user *source,
@@ -373,6 +372,7 @@ static ssize_t ivtvfb_write(struct fb_info *info, const char __user *buf,
         unsigned long p = *ppos;
         void *dst;
         int err = 0;
+        int dma_err;
         unsigned long total_size;
         struct ivtv *itv = (struct ivtv *) info->par;
         unsigned long dma_offset =
@@ -399,7 +399,6 @@ static ssize_t ivtvfb_write(struct fb_info *info, const char __user *buf,
         if (count + p > total_size) {
                 if (!err)
                         err = -ENOSPC;
-
                 count = total_size - p;
         }
 
@@ -408,39 +407,34 @@ static ssize_t ivtvfb_write(struct fb_info *info, const char __user *buf,
         if (info->fbops->fb_sync)
                 info->fbops->fb_sync(info);
 
-        if (!access_ok(VERIFY_READ, buf, count)) {
-                IVTVFB_WARN("Invalid userspace pointer 0x%08lx\n",
-                        (unsigned long)buf);
-                err = -EFAULT;
-        }
-
-        if (!err) {
-                /* If transfer size > threshold and both src/dst
-                addresses are aligned, use DMA */
-                if (count >= 4096 &&
-                    ((unsigned long)buf & 3) == ((unsigned long)dst & 3)) {
-                        /* Odd address = can't DMA. Align */
-                        if ((unsigned long)dst & 3) {
-                                lead = 4 - ((unsigned long)dst & 3);
-                                memcpy(dst, buf, lead);
-                                buf += lead;
-                                dst += lead;
-                        }
-                        /* DMA resolution is 32 bits */
-                        if ((count - lead) & 3)
-                                tail = (count - lead) & 3;
-                        /* DMA the data */
-                        dma_size = count - lead - tail;
-                        err = ivtvfb_prep_dec_dma_to_device(itv,
-                               p + lead + dma_offset, (void *)buf, dma_size);
-                        dst += dma_size;
-                        buf += dma_size;
-                        /* Copy any leftover data */
-                        if (tail)
-                                memcpy(dst, buf, tail);
-                } else {
-                        memcpy(dst, buf, count);
+        /* If transfer size > threshold and both src/dst
+        addresses are aligned, use DMA */
+        if (count >= 4096 &&
+            ((unsigned long)buf & 3) == ((unsigned long)dst & 3)) {
+                /* Odd address = can't DMA. Align */
+                if ((unsigned long)dst & 3) {
+                        lead = 4 - ((unsigned long)dst & 3);
+                        if (copy_from_user(dst, buf, lead))
+                                return -EFAULT;
+                        buf += lead;
+                        dst += lead;
                 }
+                /* DMA resolution is 32 bits */
+                if ((count - lead) & 3)
+                        tail = (count - lead) & 3;
+                /* DMA the data */
+                dma_size = count - lead - tail;
+                dma_err = ivtvfb_prep_dec_dma_to_device(itv,
+                       p + lead + dma_offset, (void __user *)buf, dma_size);
+                if (dma_err)
+                        return dma_err;
+                dst += dma_size;
+                buf += dma_size;
+                /* Copy any leftover data */
+                if (tail && copy_from_user(dst, buf, tail))
+                        return -EFAULT;
+        } else if (copy_from_user(dst, buf, count)) {
+                return -EFAULT;
         }
 
         if  (!err)
@@ -463,9 +457,12 @@ static int ivtvfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long ar
                         vblank.flags = FB_VBLANK_HAVE_COUNT |FB_VBLANK_HAVE_VCOUNT |
                                         FB_VBLANK_HAVE_VSYNC;
                         trace = read_reg(0x028c0) >> 16;
-                        if (itv->is_50hz && trace > 312) trace -= 312;
-                        else if (itv->is_60hz && trace > 262) trace -= 262;
-                        if (trace == 1) vblank.flags |= FB_VBLANK_VSYNCING;
+                        if (itv->is_50hz && trace > 312)
+                                trace -= 312;
+                        else if (itv->is_60hz && trace > 262)
+                                trace -= 262;
+                        if (trace == 1)
+                                vblank.flags |= FB_VBLANK_VSYNCING;
                         vblank.count = itv->last_vsync_field;
                         vblank.vcount = trace;
                         vblank.hcount = 0;
@@ -476,7 +473,8 @@ static int ivtvfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long ar
 
                 case FBIO_WAITFORVSYNC:
                         prepare_to_wait(&itv->vsync_waitq, &wait, TASK_INTERRUPTIBLE);
-                        if (!schedule_timeout(msecs_to_jiffies(50))) rc = -ETIMEDOUT;
+                        if (!schedule_timeout(msecs_to_jiffies(50)))
+                                rc = -ETIMEDOUT;
                         finish_wait(&itv->vsync_waitq, &wait);
                         return rc;