[PATCH] usb: dwc2: Fix call location of dwc2_check_core_endianness

From: Bruno Meirelles Herrera
Date: Mon Aug 27 2018 - 17:43:16 EST


Some SoC/IP as STM32F469, the snpsid can only be read after clock is
enabled, otherwise it will read as 0, and the dwc2_check_core_endianness
will assume the core and AHB have opposite endianness, leading to the
following error:

[ 1.976339] dwc2 50000000.usb: 50000000.usb supply vusb_d not found, using dummy regulator
[ 1.986124] dwc2 50000000.usb: Linked as a consumer to regulator.0
[ 1.992711] dwc2 50000000.usb: 50000000.usb supply vusb_a not found, using dummy regulator
[ 2.003672] dwc2 50000000.usb: dwc2_core_reset: HANG! AHB Idle timeout GRSTCTL GRSTCTL_AHBIDLE
[ 2.015176] dwc2: probe of 50000000.usb failed with error -16

The proposed patch changes the location where dwc2_check_core_endianness
is called, allowing the clock peripheral to be enabled first.

Signed-off-by: Bruno Meirelles Herrera <bmh@xxxxxxxxxxxx>
---
drivers/usb/dwc2/platform.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 9a53a58e676e..577642895b57 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -412,8 +412,6 @@ static int dwc2_driver_probe(struct platform_device *dev)
dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
(unsigned long)res->start, hsotg->regs);

- hsotg->needs_byte_swap = dwc2_check_core_endianness(hsotg);
-
retval = dwc2_lowlevel_hw_init(hsotg);
if (retval)
return retval;
@@ -438,6 +436,8 @@ static int dwc2_driver_probe(struct platform_device *dev)
if (retval)
return retval;

+ hsotg->needs_byte_swap = dwc2_check_core_endianness(hsotg);
+
retval = dwc2_get_dr_mode(hsotg);
if (retval)
goto error;
--
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