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

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