From 70cdb930f7e97e0abe4ec4ac30e63ada490ef375 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 28 Jun 2022 11:21:43 +0300 Subject: [PATCH] usb: gadget: aspeed_udc: fix handling of tx_len == 0 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. Fixes: c09b1f372e74 ("usb: gadget: aspeed_udc: cleanup loop in ast_dma_descriptor_setup()") Reported-by: Neal Liu Reviewed-by: Neal Liu Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/Yrq6F5okoX1y05rT@kili Signed-off-by: Greg Kroah-Hartman --- 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 d75a4e0..01968e2 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; -- 2.7.4