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Date:   Wed, 20 Apr 2022 16:08:17 +0900
From:   paul.elder@ideasonboard.com
To:     "Haifeng" <haifeng.li@timesintelli.com>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH]usb: gadget: musb: Fix the DMA transfer error for
 Isochronous transfers
Message-ID: <20220420070817.GC3237525@pyrite.rasen.tech>
References: <001401d85247$2c66cd40$853467c0$@timesintelli.com>
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In-Reply-To: <001401d85247$2c66cd40$853467c0$@timesintelli.com>
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Hello Haifeng,

On Sun, Apr 17, 2022 at 06:37:44PM +0800, Haifeng wrote:
> For Isochronous transfer mode, the ISO bit should be kept in CSR.
> Otherwise, the DMA transfer will be terminated unexpected since
> the ISO bit is missed once the last packet is a short packet.
> 
> Signed-off-by: Haifeng Li <haifeng.li@timesintelli.com>

Looks good to me.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

> ---
>  drivers/usb/musb/musb_gadget.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> index 51274b87f46c..b99faf627dce 100644
> --- a/drivers/usb/musb/musb_gadget.c
> +++ b/drivers/usb/musb/musb_gadget.c
> @@ -482,7 +482,7 @@ void musb_g_tx(struct musb *musb, u8 epnum)
>  			if (csr & MUSB_TXCSR_TXPKTRDY)
>  				return;
>  
> -			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
> +			musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_MODE
>  					| MUSB_TXCSR_TXPKTRDY);
>  			request->zero = 0;
>  		}
> -- 
> 2.17.1
>