diff mbox series

[RESEND,v3,04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

Message ID 1599726112-4439-4-git-send-email-chunfeng.yun@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [RESEND,v3,01/11] usb: early: convert to readl_poll_timeout_atomic() | expand

Commit Message

Chunfeng Yun (云春峰) Sept. 10, 2020, 8:21 a.m. UTC
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>
---
v2~v3: no changes
---
 drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

Comments

Yoshihiro Shimoda Sept. 10, 2020, 12:56 p.m. UTC | #1
Hi Chunfeng,

Thank you for the patch!

> From: Chunfeng Yun, Sent: Thursday, September 10, 2020 5:22 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>
> ---
> 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..74f836f 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),
> +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);

Some parentheses are not needed like below:

	retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
			val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000);


>  	release_firmware(fw);
> 
> @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> 
>  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
>  {
> -	int timeout = 1000;
> +	int retval;
>  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> 
> -	while (timeout > 0) {
> -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> -		if ((val & mask) == mask)
> -			return true;
> -		udelay(1);
> -		timeout--;
> -	}
> -
> -	return false;
> +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> +			val, ((val & mask) == mask), 1, 1000);

Likewise above:
	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
			val, (val & mask) == mask, 1, 1000);

> +	return !!retval;

This breaks the code. If I changed this to "return retval < 0 ? false : true;",
it works again.

Best regards,
Yoshihiro Shimoda
Daniel Thompson Sept. 10, 2020, 1:12 p.m. UTC | #2
On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> 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>
> ---
> 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..74f836f 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),
> +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);

Directly assigning to retval at this point will clobber a previous
-ETIMEDOUT error.

In other words if there is a timeout waiting for FW_SET_DATA0, but not for
DW_SUCCESS, then we will return the wrong return value.


Daniel.


>  
>  	release_firmware(fw);
>  
> @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  
>  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
>  {
> -	int timeout = 1000;
> +	int retval;
>  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
>  
> -	while (timeout > 0) {
> -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> -		if ((val & mask) == mask)
> -			return true;
> -		udelay(1);
> -		timeout--;
> -	}
> -
> -	return false;
> +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> +			val, ((val & mask) == mask), 1, 1000);
> +	return !!retval;

This function returns a bool so !! is either wrong or redundant... I
think in this case it is wrong and should be a single ! .


Daniel.
Chunfeng Yun (云春峰) Sept. 11, 2020, 2:21 a.m. UTC | #3
On Thu, 2020-09-10 at 12:56 +0000, Yoshihiro Shimoda wrote:
> Hi Chunfeng,
> 
> Thank you for the patch!
> 
> > From: Chunfeng Yun, Sent: Thursday, September 10, 2020 5:22 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>
> > ---
> > 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..74f836f 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),
> > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> 
> Some parentheses are not needed like below:
> 
> 	retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> 			val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000);
> 
Ok, will modify it

> 
> >  	release_firmware(fw);
> > 
> > @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > 
> >  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
> >  {
> > -	int timeout = 1000;
> > +	int retval;
> >  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> > 
> > -	while (timeout > 0) {
> > -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> > -		if ((val & mask) == mask)
> > -			return true;
> > -		udelay(1);
> > -		timeout--;
> > -	}
> > -
> > -	return false;
> > +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> > +			val, ((val & mask) == mask), 1, 1000);
> 
> Likewise above:
> 	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> 			val, (val & mask) == mask, 1, 1000);
> 
> > +	return !!retval;
> 
> This breaks the code. If I changed this to "return retval < 0 ? false : true;",
> it works again.
Oops, my bad, will fix it

Thanks a lot

> 
> Best regards,
> Yoshihiro Shimoda
>
Chunfeng Yun (云春峰) Sept. 11, 2020, 2:33 a.m. UTC | #4
On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > 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>
> > ---
> > 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..74f836f 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),
> > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> 
> Directly assigning to retval at this point will clobber a previous
> -ETIMEDOUT error.
> 
> In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> DW_SUCCESS, then we will return the wrong return value.
Yes, agree with you, but seems I keep its original logic unchanged.

Hi Yoshihiro,

  What do think about Daniel's suggestion? should I fix it up?

> 
> 
> Daniel.
> 
> 
> >  
> >  	release_firmware(fw);
> >  
> > @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  
> >  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
> >  {
> > -	int timeout = 1000;
> > +	int retval;
> >  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> >  
> > -	while (timeout > 0) {
> > -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> > -		if ((val & mask) == mask)
> > -			return true;
> > -		udelay(1);
> > -		timeout--;
> > -	}
> > -
> > -	return false;
> > +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> > +			val, ((val & mask) == mask), 1, 1000);
> > +	return !!retval;
> 
> This function returns a bool so !! is either wrong or redundant... I
> think in this case it is wrong and should be a single ! .
Yes, will fix it

Thanks a lot
> 
> 
> Daniel.
Yoshihiro Shimoda Sept. 11, 2020, 3:13 a.m. UTC | #5
Hi Daniel, Chunfeng,

> From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> 
> On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > 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>
> > > ---
> > > 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..74f836f 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),
> > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> >
> > Directly assigning to retval at this point will clobber a previous
> > -ETIMEDOUT error.
> >
> > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > DW_SUCCESS, then we will return the wrong return value.

Thank you for your comment! I didn't realized this.

> Yes, agree with you, but seems I keep its original logic unchanged.
> Hi Yoshihiro,
> 
>   What do think about Daniel's suggestion? should I fix it up?

I think you should fix it up like below:

if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */

Otherwise, the xhci_rcar_download_firmware() cannot return -ETIMEDOUT if
timeout happened on the previous poll [1].

[1]
+		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
+				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
+				1, 10000);

Best regards,
Yoshihiro Shimoda
Chunfeng Yun (云春峰) Sept. 11, 2020, 4:12 a.m. UTC | #6
On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> Hi Daniel, Chunfeng,
> 
> > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > 
> > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > 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>
> > > > ---
> > > > 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..74f836f 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)
How about free firmware and return error number here ? instead of break

> > > >  			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),
> > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > >
> > > Directly assigning to retval at this point will clobber a previous
> > > -ETIMEDOUT error.
> > >
> > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > DW_SUCCESS, then we will return the wrong return value.
> 
> Thank you for your comment! I didn't realized this.
> 
> > Yes, agree with you, but seems I keep its original logic unchanged.
> > Hi Yoshihiro,
> > 
> >   What do think about Daniel's suggestion? should I fix it up?
> 
> I think you should fix it up like below:
> 
> if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */

readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
likes what I did, doesn't fix it.

> 
> Otherwise, the xhci_rcar_download_firmware() cannot return -ETIMEDOUT if
> timeout happened on the previous poll [1].
> 
> [1]
> +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> +				1, 10000);
> 
> Best regards,
> Yoshihiro Shimoda
>
Yoshihiro Shimoda Sept. 11, 2020, 4:57 a.m. UTC | #7
Hi Chunfeng,

> From: Chunfeng Yun, Sent: Friday, September 11, 2020 1:13 PM
> 
> On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> > Hi Daniel, Chunfeng,
> >
> > > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > >
> > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > 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>
> > > > > ---
> > > > > 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..74f836f 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)
> How about free firmware and return error number here ? instead of break

I think clearing CTRL_ENABLE code below is needed.
And, I think this patch should not change a lot of things...

> > > > >  			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),
> > > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > >
> > > > Directly assigning to retval at this point will clobber a previous
> > > > -ETIMEDOUT error.
> > > >
> > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > DW_SUCCESS, then we will return the wrong return value.
> >
> > Thank you for your comment! I didn't realized this.
> >
> > > Yes, agree with you, but seems I keep its original logic unchanged.
> > > Hi Yoshihiro,
> > >
> > >   What do think about Daniel's suggestion? should I fix it up?
> >
> > I think you should fix it up like below:
> >
> > if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> > 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */
> 
> readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
> likes what I did, doesn't fix it.

readl_poll_timeout_atomic() returns 0 if timeout doesn't happen.
So, when my suggestion code runs, the retval is not overwritten if
the readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL...) returns 0.

Best regards,
Yoshihiro Shimoda
Daniel Thompson Sept. 11, 2020, 8:34 a.m. UTC | #8
On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > 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>
> > > ---
> > > 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..74f836f 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),
> > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > 
> > Directly assigning to retval at this point will clobber a previous
> > -ETIMEDOUT error.
> > 
> > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > DW_SUCCESS, then we will return the wrong return value.
>
> Yes, agree with you, but seems I keep its original logic unchanged.

I disagree.

Your patch does not preserve the original logic. Your patch explicitly
sets retval to zero if the second loop succeeds. The original code does
not do this. As a result there is a change of return code for one of the
error paths.


Daniel.
Chunfeng Yun (云春峰) Sept. 11, 2020, 9:27 a.m. UTC | #9
On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > 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>
> > > > ---
> > > > 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..74f836f 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;
Here will set it 0 too

> > > > -			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_SUCCESS), 1, 10000);
> > > 
> > > Directly assigning to retval at this point will clobber a previous
> > > -ETIMEDOUT error.
> > > 
> > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > DW_SUCCESS, then we will return the wrong return value.
> >
> > Yes, agree with you, but seems I keep its original logic unchanged.
> 
> I disagree.
> 
> Your patch does not preserve the original logic. Your patch explicitly
> sets retval to zero if the second loop succeeds. The original code does
> not do this. As a result there is a change of return code for one of the
> error paths.
> 
> 
> Daniel.
Daniel Thompson Sept. 11, 2020, 9:48 a.m. UTC | #10
On Fri, Sep 11, 2020 at 05:27:22PM +0800, Chunfeng Yun wrote:
> On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> > On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > 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>
> > > > > ---
> > > > > 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..74f836f 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;
> Here will set it 0 too

Doh...

Thanks.


Daniel.


> 
> > > > > -			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_SUCCESS), 1, 10000);
> > > > 
> > > > Directly assigning to retval at this point will clobber a previous
> > > > -ETIMEDOUT error.
> > > > 
> > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > DW_SUCCESS, then we will return the wrong return value.
> > >
> > > Yes, agree with you, but seems I keep its original logic unchanged.
> > 
> > I disagree.
> > 
> > Your patch does not preserve the original logic. Your patch explicitly
> > sets retval to zero if the second loop succeeds. The original code does
> > not do this. As a result there is a change of return code for one of the
> > error paths.
> > 
> > 
> > Daniel.
>
Yoshihiro Shimoda Sept. 11, 2020, 9:58 a.m. UTC | #11
Hi Chunfeng,

> From: Daniel Thompson, Sent: Friday, September 11, 2020 6:49 PM
> 
> On Fri, Sep 11, 2020 at 05:27:22PM +0800, Chunfeng Yun wrote:
> > On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> > > On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > > 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>
> > > > > > ---
> > > > > > 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..74f836f 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;
> > Here will set it 0 too
> 
> Doh...
> 
> Thanks.

Ah, now I also understood your patch was logically unchanged.
Thanks!

Best regards,
Yoshihiro Shimoda
Chunfeng Yun (云春峰) Sept. 11, 2020, 11:46 a.m. UTC | #12
On Fri, 2020-09-11 at 04:57 +0000, Yoshihiro Shimoda wrote:
> Hi Chunfeng,
> 
> > From: Chunfeng Yun, Sent: Friday, September 11, 2020 1:13 PM
> > 
> > On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> > > Hi Daniel, Chunfeng,
> > >
> > > > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > > >
> > > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > > 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>
> > > > > > ---
> > > > > > 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..74f836f 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)
> > How about free firmware and return error number here ? instead of break
> 
> I think clearing CTRL_ENABLE code below is needed.
> And, I think this patch should not change a lot of things...
Ok, thanks

> 
> > > > > >  			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),
> > > > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > > >
> > > > > Directly assigning to retval at this point will clobber a previous
> > > > > -ETIMEDOUT error.
> > > > >
> > > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > > DW_SUCCESS, then we will return the wrong return value.
> > >
> > > Thank you for your comment! I didn't realized this.
> > >
> > > > Yes, agree with you, but seems I keep its original logic unchanged.
> > > > Hi Yoshihiro,
> > > >
> > > >   What do think about Daniel's suggestion? should I fix it up?
> > >
> > > I think you should fix it up like below:
> > >
> > > if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> > > 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */
> > 
> > readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
> > likes what I did, doesn't fix it.
> 
> readl_poll_timeout_atomic() returns 0 if timeout doesn't happen.
> So, when my suggestion code runs, the retval is not overwritten if
> the readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL...) returns 0.
> 
> Best regards,
> Yoshihiro Shimoda
>
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
index c1025d3..74f836f 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),
+			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
 
 	release_firmware(fw);
 
@@ -200,18 +187,12 @@  static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
 
 static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
 {
-	int timeout = 1000;
+	int retval;
 	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
 
-	while (timeout > 0) {
-		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
-		if ((val & mask) == mask)
-			return true;
-		udelay(1);
-		timeout--;
-	}
-
-	return false;
+	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
+			val, ((val & mask) == mask), 1, 1000);
+	return !!retval;
 }
 
 /* This function needs to initialize a "phy" of usb before */