Re: [RESEND/PATCH 6/6] USB: musb-gadget: fix dma length in txstate

From: Felipe Balbi
Date: Wed Sep 15 2010 - 03:09:59 EST


On Tue, Sep 14, 2010 at 12:43:25PM -0500, Sergei Shtylyov wrote:
Hello.

tom.leiming@xxxxxxxxx wrote:

From: Ming Lei <tom.leiming@xxxxxxxxx>

DMA length should not go beyond the availabe space of request buffer,
so fix it.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Felipe Balbi <me@xxxxxxxxxxxxxxx>
Cc: Anand Gadiyar <gadiyar@xxxxxx>
Cc: Mike Frysinger <vapier@xxxxxxxxxx>
Cc: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>

[...]

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index fa826f9..cacae96 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -300,6 +300,11 @@ static void txstate(struct musb *musb, struct musb_request *req)
#ifndef CONFIG_MUSB_PIO_ONLY
if (is_dma_capable() && musb_ep->dma) {
struct dma_controller *c = musb->dma_controller;
+ size_t request_size;
+
+ /* setup DMA, then program endpoint CSR */
+ request_size = min_t(size_t, request->length - request->actual,
+ musb_ep->dma->max_len);

Er, you're moving this from under #ifdef CONFIG_USB_INVENTRA_DMA to the
common code, right? Do you know that not all DMA drivers initialize max_len? For
example CPPI driver doesn't, so it's left at zero. You're going to break DMA for
CPPI. Please extend your patch, adding cppi_dma.c to it.

yes, please set some value on cppi_dma.c max_len field.

--
balbi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/