usb: gadget: aspeed_udc: cleanup loop in ast_dma_descriptor_setup()

The "chunk >= 0" condition does not work because count is a u32.
Also, really we shouldn't enter the loop when "chunk" is zero.

Once that condition is fixed then there is no need for the "last"
variable.  I reversed the "if (chunk <= ep->chunk_max)" as well.
The new loop is much simpler.

Fixes: 055276c13205 ("usb: gadget: add Aspeed ast2600 udc driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/Yq2SvM2bbrtSd1H9@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/aspeed_udc.c b/drivers/usb/gadget/udc/aspeed_udc.c
index 6c91f7f..4dead40 100644 (file)
--- a/drivers/usb/gadget/udc/aspeed_udc.c
+++ b/drivers/usb/gadget/udc/aspeed_udc.c
@@ -476,8 +476,8 @@ static int ast_dma_descriptor_setup(struct ast_udc_ep *ep, u32 dma_buf,
 {
        struct ast_udc_dev *udc = ep->udc;
        struct device *dev = &udc->pdev->dev;
-       u32 offset, chunk;
-       int count, last;
+       int chunk, count;
+       u32 offset;
 
        if (!ep->descs) {
                dev_warn(dev, "%s: Empty DMA descs list failure\n",
@@ -486,30 +486,28 @@ static int ast_dma_descriptor_setup(struct ast_udc_ep *ep, u32 dma_buf,
        }
 
        chunk = tx_len;
-       offset = count = last = 0;
+       offset = count = 0;
 
        EP_DBG(ep, "req @%p, %s:%d, %s:0x%x, %s:0x%x\n", req,
               "wptr", ep->descs_wptr, "dma_buf", dma_buf,
               "tx_len", tx_len);
 
        /* Create Descriptor Lists */
-       while (chunk >= 0 && !last && count < AST_UDC_DESCS_COUNT) {
+       while (chunk > 0 && count < AST_UDC_DESCS_COUNT) {
 
                ep->descs[ep->descs_wptr].des_0 = dma_buf + offset;
 
-               if (chunk <= ep->chunk_max) {
-                       ep->descs[ep->descs_wptr].des_1 = chunk;
-                       last = 1;
-               } else {
+               if (chunk > ep->chunk_max)
                        ep->descs[ep->descs_wptr].des_1 = ep->chunk_max;
-                       chunk -= ep->chunk_max;
-               }
+               else
+                       ep->descs[ep->descs_wptr].des_1 = chunk;
+
+               chunk -= ep->chunk_max;
 
-               EP_DBG(ep, "descs[%d]: 0x%x 0x%x, last:%d\n",
+               EP_DBG(ep, "descs[%d]: 0x%x 0x%x\n",
                       ep->descs_wptr,
                       ep->descs[ep->descs_wptr].des_0,
-                      ep->descs[ep->descs_wptr].des_1,
-                      last);
+                      ep->descs[ep->descs_wptr].des_1);
 
                if (count == 0)
                        req->saved_dma_wptr = ep->descs_wptr;