[PATCH v2 1/9] usb: dwc3: pci: Add "snps,dis_u2_susphy_quirk" for Intel Bay Trail

[Hans de Goede <hdegoede@redhat.com>]

Commit e0082698b689 ("usb: dwc3: ulpi: conditionally resume ULPI PHY")
fixed an issue where ULPI transfers would timeout if any requests where
send to the phy sometime after init, giving it enough time to auto-suspend.

Commit e5f4ca3fce90 ("usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend
regression") changed the behavior to instead of clearing the
DWC3_GUSB2PHYCFG_SUSPHY bit, add an extra sleep when it is set.

But on Bay Trail devices, when phy_set_mode() gets called during init,
this leads to errors like these:
[   28.451522] tusb1210 dwc3.ulpi: error -110 writing val 0x01 to reg 0x0a
[   28.464089] tusb1210 dwc3.ulpi: error -110 writing val 0x01 to reg 0x0a

Add "snps,dis_u2_susphy_quirk" to the settings for Bay Trail devices to
fix this. This restores the old behavior for Bay Trail devices, since
previously the DWC3_GUSB2PHYCFG_SUSPHY bit would get cleared on the first
ulpi_read/_write() and then was never set again.

Fixes: e5f4ca3fce90 ("usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend regression")
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/usb/dwc3/dwc3-pci.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
index 7ff8fc8f79a9..022341aef400 100644
--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -119,6 +119,13 @@ static const struct property_entry dwc3_pci_intel_properties[] = {
 	{}
 };
 
+static const struct property_entry dwc3_pci_intel_byt_properties[] = {
+	PROPERTY_ENTRY_STRING("dr_mode", "peripheral"),
+	PROPERTY_ENTRY_BOOL("snps,dis_u2_susphy_quirk"),
+	PROPERTY_ENTRY_BOOL("linux,sysdev_is_parent"),
+	{}
+};
+
 static const struct property_entry dwc3_pci_mrfld_properties[] = {
 	PROPERTY_ENTRY_STRING("dr_mode", "otg"),
 	PROPERTY_ENTRY_STRING("linux,extcon-name", "mrfld_bcove_pwrsrc"),
@@ -161,6 +168,10 @@ static const struct software_node dwc3_pci_intel_swnode = {
 	.properties = dwc3_pci_intel_properties,
 };
 
+static const struct software_node dwc3_pci_intel_byt_swnode = {
+	.properties = dwc3_pci_intel_byt_properties,
+};
+
 static const struct software_node dwc3_pci_intel_mrfld_swnode = {
 	.properties = dwc3_pci_mrfld_properties,
 };
@@ -344,7 +355,7 @@ static const struct pci_device_id dwc3_pci_id_table[] = {
 	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BYT),
-	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
+	  (kernel_ulong_t) &dwc3_pci_intel_byt_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD),
 	  (kernel_ulong_t) &dwc3_pci_intel_mrfld_swnode, },
-- 
2.33.1