RE: [PATCH v4 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Mathias Nyman <mathias.nyman@intel.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Sumit Garg <sumit.garg@linaro.org>,
	Lee Jones <lee.jones@linaro.org>, Jann Horn <jannh@google.com>,
	Jason Yan <yanaijie@huawei.com>, Arnd Bergmann <arnd@arndb.de>,
	Chuhong Yuan <hslester96@gmail.com>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	"Ben Dooks (Codethink)" <ben.dooks@codethink.co.uk>,
	Saurav Girepunje <saurav.girepunje@gmail.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-mediatek@lists.infradead.org" 
	<linux-mediatek@lists.infradead.org>,
	Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Felipe Balbi <balbi@kernel.org>
Subject: RE: [PATCH v4 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()
Date: Wed, 23 Sep 2020 08:47:14 +0000	[thread overview]
Message-ID: <TY2PR01MB3692184CBB3C12EE8A02BA48D8380@TY2PR01MB3692.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <1600668815-12135-4-git-send-email-chunfeng.yun@mediatek.com>

Hi Chungeng,

Thank you for the patch!

> From: Chunfeng Yun, Sent: Monday, September 21, 2020 3:13 PM
> 
> Use readl_poll_timeout_atomic() to simplify code
> 
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v4: changes
>     1. remove unnecessary parentheses suggested by Yoshihiro
>     2. fix the wrong return value suggested by Yoshihiro & Daniel
> 
> v2~v3: no changes
> ---
>  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
>  1 file changed, 12 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> index c1025d3..1bc4fe7 100644
> --- a/drivers/usb/host/xhci-rcar.c
> +++ b/drivers/usb/host/xhci-rcar.c
> @@ -6,6 +6,7 @@
>   */
> 
>  #include <linux/firmware.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/of.h>
> @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  	void __iomem *regs = hcd->regs;
>  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
>  	const struct firmware *fw;
> -	int retval, index, j, time;
> -	int timeout = 10000;
> +	int retval, index, j;
>  	u32 data, val, temp;
>  	u32 quirks = 0;
>  	const struct soc_device_attribute *attr;
> @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
>  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> 
> -		for (time = 0; time < timeout; time++) {
> -			val = readl(regs + RCAR_USB3_DL_CTRL);
> -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> -				break;
> -			udelay(1);
> -		}
> -		if (time == timeout) {
> -			retval = -ETIMEDOUT;
> +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> +				1, 10000);
> +		if (retval < 0)
>  			break;
> -		}
>  	}
> 
>  	temp = readl(regs + RCAR_USB3_DL_CTRL);
>  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
>  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> 
> -	for (time = 0; time < timeout; time++) {
> -		val = readl(regs + RCAR_USB3_DL_CTRL);
> -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> -			retval = 0;
> -			break;
> -		}
> -		udelay(1);
> -	}
> -	if (time == timeout)
> -		retval = -ETIMEDOUT;
> +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),

We can also remove these unnecessary parentheses like below.

+	retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,

After fixed this:

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Best regards,
Yoshihiro Shimoda