Revert "usb: dwc2: Move reset into dwc2_get_hwparams()"

This reverts commit 263b7fb557f7 ("usb: dwc2: Move reset into
dwc2_get_hwparams()") due to regression found on bcm2835 platform. USB
ethernet fails, due to being unable to pick up proper parameters when
performing a plain reset before reading hw params.

Below shows the results of the gnptxfsiz and hptxfsiz with and before
and after reverting this (from Stefan Wahren):

So here is the probe result before Patch 1 is applied:

[    1.283148] dwc2 20980000.usb: Configuration mismatch. dr_mode forced to host
[    1.313894] dwc2 20980000.usb: gnptxfsiz=00201000
[    1.314104] dwc2 20980000.usb: hptxfsiz=00000000
[    1.353908] dwc2 20980000.usb: 256 invalid for host_nperio_tx_fifo_size. Check HW configuration.
[    1.354262] dwc2 20980000.usb: 512 invalid for host_perio_tx_fifo_size. Check HW configuration.
[    1.394249] dwc2 20980000.usb: DWC OTG Controller
[    1.394561] dwc2 20980000.usb: new USB bus registered, assigned bus number 1
[    1.394917] dwc2 20980000.usb: irq 33, io mem 0x00000000

And here is the probe result after Patch 1 is applied:

[    1.280107] dwc2 20980000.usb: Configuration mismatch. dr_mode forced to host
[    1.353949] dwc2 20980000.usb: gnptxfsiz=01001000
[    1.354166] dwc2 20980000.usb: hptxfsiz=02002000
[    1.434301] dwc2 20980000.usb: DWC OTG Controller
[    1.434616] dwc2 20980000.usb: new USB bus registered, assigned bus number 1
[    1.434973] dwc2 20980000.usb: irq 33, io mem 0x00000000

Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
Reported-by: Remi Pommarel <repk@triplefau.lt>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 39a0fa8..1489d31 100644 (file)
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -3278,9 +3278,6 @@ static void dwc2_get_dev_hwparams(struct dwc2_hsotg *hsotg)
 /**
  * During device initialization, read various hardware configuration
  * registers and interpret the contents.
- *
- * This should be called during driver probe. It will perform a core
- * soft reset in order to get the reset values of the parameters.
  */
 int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
 {
@@ -3288,7 +3285,6 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
        unsigned width;
        u32 hwcfg1, hwcfg2, hwcfg3, hwcfg4;
        u32 grxfsiz;
-       int retval;
 
        /*
         * Attempt to ensure this device is really a DWC_otg Controller.
@@ -3308,10 +3304,6 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
                hw->snpsid >> 12 & 0xf, hw->snpsid >> 8 & 0xf,
                hw->snpsid >> 4 & 0xf, hw->snpsid & 0xf, hw->snpsid);
 
-       retval = dwc2_core_reset(hsotg);
-       if (retval)
-               return retval;
-
        hwcfg1 = dwc2_readl(hsotg->regs + GHWCFG1);
        hwcfg2 = dwc2_readl(hsotg->regs + GHWCFG2);
        hwcfg3 = dwc2_readl(hsotg->regs + GHWCFG3);

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 510f787..690b9fd 100644 (file)
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -530,7 +530,13 @@ static int dwc2_driver_probe(struct platform_device *dev)
        if (retval)
                return retval;
 
-       /* Reset the controller and detect hardware config values */
+       /*
+        * Reset before dwc2_get_hwparams() then it could get power-on real
+        * reset value form registers.
+        */
+       dwc2_core_reset_and_force_dr_mode(hsotg);
+
+       /* Detect config values from hardware */
        retval = dwc2_get_hwparams(hsotg);
        if (retval)
                goto error;