The bug is that we should still enter this loop if "tx_len" is zero.
After adding the "last" variable, then the "chunk >= 0" condition is no
longer required but I left it for readability.
Reported-by: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
Fixes: c09b1f372e74 ("usb: gadget: aspeed_udc: cleanup loop in ast_dma_descriptor_setup()")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
---
v3: We went back and forth on the style on this. This is just v1 but
with Neal's Reviewed-by.
drivers/usb/gadget/udc/aspeed_udc.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/udc/aspeed_udc.c b/drivers/usb/gadget/udc/aspeed_udc.c
index d75a4e070bf7..01968e2167f9 100644
--- a/drivers/usb/gadget/udc/aspeed_udc.c
+++ b/drivers/usb/gadget/udc/aspeed_udc.c
@@ -476,6 +476,7 @@ 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;
+ bool last = false;
int chunk, count;
u32 offset;
@@ -493,14 +494,16 @@ static int ast_dma_descriptor_setup(struct ast_udc_ep *ep, u32 dma_buf,
"tx_len", tx_len);
/* Create Descriptor Lists */
- while (chunk > 0 && count < AST_UDC_DESCS_COUNT) {
+ while (chunk >= 0 && !last && count < AST_UDC_DESCS_COUNT) {
ep->descs[ep->descs_wptr].des_0 = dma_buf + offset;
- if (chunk > ep->chunk_max)
+ if (chunk > ep->chunk_max) {
ep->descs[ep->descs_wptr].des_1 = ep->chunk_max;
- else
+ } else {
ep->descs[ep->descs_wptr].des_1 = chunk;
+ last = true;
+ }
chunk -= ep->chunk_max;
--
2.35.1
