> 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.
>
Use either "chunk >=0" or "last".
I think the former is more simpler.
> 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>
> ---
> 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
