diff mbox series

[1/1] usb: gadget: aspeed: fix stop dma register setting.

Message ID 20210108081238.10199-2-ryan_chen@aspeedtech.com
State New
Headers show
Series Fix vhub engine stop dma register setting. | expand

Commit Message

Ryan Chen Jan. 8, 2021, 8:12 a.m. UTC
The vhub engine has two dma mode, one is descriptor list, another
is single stage DMA. Each mode has different stop register setting.
Descriptor list operation (bit2) : 0 disable reset, 1: enable reset
Single mode operation (bit0) : 0 : disable, 1: enable

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 drivers/usb/gadget/udc/aspeed-vhub/epn.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Joel Stanley Jan. 11, 2021, 2:24 a.m. UTC | #1
On Fri, 8 Jan 2021 at 08:13, Ryan Chen <ryan_chen@aspeedtech.com> wrote:
>

> The vhub engine has two dma mode, one is descriptor list, another

> is single stage DMA. Each mode has different stop register setting.

> Descriptor list operation (bit2) : 0 disable reset, 1: enable reset

> Single mode operation (bit0) : 0 : disable, 1: enable

>

> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>

> ---

>  drivers/usb/gadget/udc/aspeed-vhub/epn.c | 5 ++++-

>  1 file changed, 4 insertions(+), 1 deletion(-)

>

> diff --git a/drivers/usb/gadget/udc/aspeed-vhub/epn.c b/drivers/usb/gadget/udc/aspeed-vhub/epn.c

> index 0bd6b20435b8..02d8bfae58fb 100644

> --- a/drivers/usb/gadget/udc/aspeed-vhub/epn.c

> +++ b/drivers/usb/gadget/udc/aspeed-vhub/epn.c

> @@ -420,7 +420,10 @@ static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,

>         u32 state, reg, loops;

>

>         /* Stop DMA activity */

> -       writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);

> +       if (ep->epn.desc_mode)

> +               writel(VHUB_EP_DMA_CTRL_RESET, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);

> +       else

> +               writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);


This looks correct, as whenever the driver re-enables DMA it uses
ep->epn.dma_conf for the value of this register. So we're not losing
any configuration by setting it to 0.

Acked-by: Joel Stanley <joel@jms.id.au>

Fixes: 7ecca2a4080c ("usb/gadget: Add driver for Aspeed SoC virtual hub")

I've cc'd Ben for his ack too.

Cheers,

Joel

>

>         /* Wait for it to complete */

>         for (loops = 0; loops < 1000; loops++) {

> --

> 2.17.1

>
diff mbox series

Patch

diff --git a/drivers/usb/gadget/udc/aspeed-vhub/epn.c b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
index 0bd6b20435b8..02d8bfae58fb 100644
--- a/drivers/usb/gadget/udc/aspeed-vhub/epn.c
+++ b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
@@ -420,7 +420,10 @@  static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,
 	u32 state, reg, loops;
 
 	/* Stop DMA activity */
-	writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	if (ep->epn.desc_mode)
+		writel(VHUB_EP_DMA_CTRL_RESET, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	else
+		writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 
 	/* Wait for it to complete */
 	for (loops = 0; loops < 1000; loops++) {