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@xxxxxxxxxxxxxxx> > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> > > > --- > > > 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.