lkml.org 
[lkml]   [2014]   [Aug]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRE: [PATCH] usb: dwc2: Read GNPTXFSIZ when in forced HOST mode.
    Date
    > From: dianders@google.com [mailto:dianders@google.com] On Behalf Of Doug Anderson
    > Sent: Thursday, August 07, 2014 5:12 PM
    >
    > On Thu, Aug 7, 2014 at 1:18 PM, Paul Zimmerman
    > <Paul.Zimmerman@synopsys.com> wrote:
    > >> From: Doug Anderson [mailto:dianders@chromium.org]
    > >> Sent: Thursday, August 07, 2014 12:48 PM
    > >>
    > >> The documentation for GNPTXFSIZ says that "For host mode, this field
    > >> is always valid." Since we're already switching to host mode for
    > >> HPTXFSIZ, let's also read GNPTXFSIZ in host mode.
    > >>
    > >> On an rk3288 SoC, without this change we see this at bootup:
    > >> dwc2 ff580000.usb: gnptxfsiz=00100400
    > >> dwc2 ff580000.usb: 128 invalid for host_nperio_tx_fifo_size. Check HW configuration.
    > >>
    > >> After this change we see:
    > >> dwc2 ff580000.usb: gnptxfsiz=04000400
    > >>
    > >> Signed-off-by: Doug Anderson <dianders@chromium.org>
    > >> ---
    > >> drivers/usb/dwc2/core.c | 6 +++---
    > >> 1 file changed, 3 insertions(+), 3 deletions(-)
    > >>
    > >> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
    > >> index 27d2c9b..c184ed43 100644
    > >> --- a/drivers/usb/dwc2/core.c
    > >> +++ b/drivers/usb/dwc2/core.c
    > >> @@ -2674,23 +2674,23 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
    > >> hwcfg2 = readl(hsotg->regs + GHWCFG2);
    > >> hwcfg3 = readl(hsotg->regs + GHWCFG3);
    > >> hwcfg4 = readl(hsotg->regs + GHWCFG4);
    > >> - gnptxfsiz = readl(hsotg->regs + GNPTXFSIZ);
    > >> grxfsiz = readl(hsotg->regs + GRXFSIZ);
    > >>
    > >> dev_dbg(hsotg->dev, "hwcfg1=%08x\n", hwcfg1);
    > >> dev_dbg(hsotg->dev, "hwcfg2=%08x\n", hwcfg2);
    > >> dev_dbg(hsotg->dev, "hwcfg3=%08x\n", hwcfg3);
    > >> dev_dbg(hsotg->dev, "hwcfg4=%08x\n", hwcfg4);
    > >> - dev_dbg(hsotg->dev, "gnptxfsiz=%08x\n", gnptxfsiz);
    > >> dev_dbg(hsotg->dev, "grxfsiz=%08x\n", grxfsiz);
    > >>
    > >> - /* Force host mode to get HPTXFSIZ exact power on value */
    > >> + /* Force host mode to get HPTXFSIZ / GNPTXFSIZ exact power on value */
    > >> gusbcfg = readl(hsotg->regs + GUSBCFG);
    > >> gusbcfg |= GUSBCFG_FORCEHOSTMODE;
    > >> writel(gusbcfg, hsotg->regs + GUSBCFG);
    > >> usleep_range(100000, 150000);
    > >>
    > >> + gnptxfsiz = readl(hsotg->regs + GNPTXFSIZ);
    > >> hptxfsiz = readl(hsotg->regs + HPTXFSIZ);
    > >> + dev_dbg(hsotg->dev, "gnptxfsiz=%08x\n", gnptxfsiz);
    > >> dev_dbg(hsotg->dev, "hptxfsiz=%08x\n", hptxfsiz);
    > >> gusbcfg = readl(hsotg->regs + GUSBCFG);
    > >> gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
    > >
    > > Nice! I wonder if this is a bug in the original driver, and they
    > > actually meant to read this register instead of HPTXFSIZ? Well, it
    > > doesn't really matter I guess.
    > >
    > > Acked-by: Paul Zimmerman <paulz@synopsys.com>
    > >
    > > You may want to resend this to Greg after -rc1 is out and he reopens
    > > his usb-next tree.
    >
    > Thanks!
    >
    > ...do you think this is a fix that needs to go in for 3.17? Is it
    > affecting anyone there?

    I don't think so. It only has an effect if the controller starts up in
    peripheral mode and then later switches to host mode, right? I think
    yours is the first dwc2 platform in the kernel with that capability.

    --
    Paul

    \
     
     \ /
      Last update: 2014-08-08 03:01    [W:5.281 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site