vme: tsi148: fix first DMA item mapping

This moves DMA mapping of the first list element to vme_list_add, the
same place where other elements mappings occur. This prevents extra
mapping or over-unmapping in the cases when vme_list_exec is called more
or less than one time respectively.

Also adds dma_mapping_error check.

Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Cc: Igor Alekseev <igor.alekseev@itep.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/vme/bridges/vme_tsi148.c b/drivers/vme/bridges/vme_tsi148.c
index 1be4136..6562348 100644 (file)
--- a/drivers/vme/bridges/vme_tsi148.c
+++ b/drivers/vme/bridges/vme_tsi148.c
@@ -1833,17 +1833,21 @@ static int tsi148_dma_list_add(struct vme_dma_list *list,
        /* Add to list */
        list_add_tail(&entry->list, &list->entries);
 
+       entry->dma_handle = dma_map_single(tsi148_bridge->parent,
+               &entry->descriptor,
+               sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
+       if (dma_mapping_error(tsi148_bridge->parent, entry->dma_handle)) {
+               dev_err(tsi148_bridge->parent, "DMA mapping error\n");
+               retval = -EINVAL;
+               goto err_dma;
+       }
+
        /* Fill out previous descriptors "Next Address" */
        if (entry->list.prev != &list->entries) {
-               prev = list_entry(entry->list.prev, struct tsi148_dma_entry,
-                       list);
-               /* We need the bus address for the pointer */
-               entry->dma_handle = dma_map_single(tsi148_bridge->parent,
-                       &entry->descriptor,
-                       sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
-
                reg_split((unsigned long long)entry->dma_handle, &address_high,
                        &address_low);
+               prev = list_entry(entry->list.prev, struct tsi148_dma_entry,
+                                 list);
                prev->descriptor.dnlau = cpu_to_be32(address_high);
                prev->descriptor.dnlal = cpu_to_be32(address_low);
 
@@ -1851,6 +1855,7 @@ static int tsi148_dma_list_add(struct vme_dma_list *list,
 
        return 0;
 
+err_dma:
 err_dest:
 err_source:
 err_align:
@@ -1921,10 +1926,6 @@ static int tsi148_dma_list_exec(struct vme_dma_list *list)
        entry = list_first_entry(&list->entries, struct tsi148_dma_entry,
                list);
 
-       entry->dma_handle = dma_map_single(tsi148_bridge->parent,
-               &entry->descriptor,
-               sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
-
        mutex_unlock(&ctrlr->mtx);
 
        reg_split(entry->dma_handle, &bus_addr_high, &bus_addr_low);