mmc: card: Avoid null pointer dereference

[pandora-kernel.git] / drivers / dma / at_hdmac.c

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index a60adbf..c60d9c1 100644 (file)
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -239,10 +239,6 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
 
        vdbg_dump_regs(atchan);
 
-       /* clear any pending interrupt */
-       while (dma_readl(atdma, EBCISR))
-               cpu_relax();
-
        channel_writel(atchan, SADDR, 0);
        channel_writel(atchan, DADDR, 0);
        channel_writel(atchan, CTRLA, 0);
@@ -682,7 +678,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                        flags);
 
        if (unlikely(!atslave || !sg_len)) {
-               dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
+               dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
                return NULL;
        }
 
@@ -710,6 +706,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
                        mem = sg_dma_address(sg);
                        len = sg_dma_len(sg);
+                       if (unlikely(!len)) {
+                               dev_dbg(chan2dev(chan),
+                                       "prep_slave_sg: sg(%d) data length is zero\n", i);
+                               goto err;
+                       }
                        mem_width = 2;
                        if (unlikely(mem & 3 || len & 3))
                                mem_width = 0;
@@ -744,6 +745,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
                        mem = sg_dma_address(sg);
                        len = sg_dma_len(sg);
+                       if (unlikely(!len)) {
+                               dev_dbg(chan2dev(chan),
+                                       "prep_slave_sg: sg(%d) data length is zero\n", i);
+                               goto err;
+                       }
                        mem_width = 2;
                        if (unlikely(mem & 3 || len & 3))
                                mem_width = 0;
@@ -777,6 +783,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 err_desc_get:
        dev_err(chan2dev(chan), "not enough descriptors available\n");
+err:
        atc_desc_put(atchan, first);
        return NULL;
 }