4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit ceb94bc52c437463f0903e61060a94a2226fb672 ]
This patch adds a safety connection way for "forced_b_device" with "workaround_for_vbus" like below:
< Example for R-Car E3 Ebisu > # modprobe <any usb gadget driver> # echo 1 > /sys/kernel/debug/ee020000.usb/b_device (connect a usb cable to host side.) # echo 2 > /sys/kernel/debug/ee020000.usb/b_device
Previous code should have connected a usb cable before the "b_device" is set to 1 on the Ebisu board. However, if xHCI driver on the board is probed, it causes some troubles: - Conflicts USB VBUS/signals between the board and another host. - "Cannot enable. Maybe the USB cable is bad?" might happen on both the board and another host with a usb hub. - Cannot enumerate a usb gadget correctly because an interruption of VBUS change happens unexpectedly.
Reported-by: Kazuya Mizuguchi kazuya.mizuguchi.ks@renesas.com Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/udc/renesas_usb3.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index cdffbd1e0316..6e34f9594159 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -358,6 +358,7 @@ struct renesas_usb3 { bool extcon_host; /* check id and set EXTCON_USB_HOST */ bool extcon_usb; /* check vbus and set EXTCON_USB */ bool forced_b_device; + bool start_to_connect; };
#define gadget_to_renesas_usb3(_gadget) \ @@ -476,7 +477,8 @@ static void usb3_init_axi_bridge(struct renesas_usb3 *usb3) static void usb3_init_epc_registers(struct renesas_usb3 *usb3) { usb3_write(usb3, ~0, USB3_USB_INT_STA_1); - usb3_enable_irq_1(usb3, USB_INT_1_VBUS_CNG); + if (!usb3->workaround_for_vbus) + usb3_enable_irq_1(usb3, USB_INT_1_VBUS_CNG); }
static bool usb3_wakeup_usb2_phy(struct renesas_usb3 *usb3) @@ -700,8 +702,7 @@ static void usb3_mode_config(struct renesas_usb3 *usb3, bool host, bool a_dev) usb3_set_mode_by_role_sw(usb3, host); usb3_vbus_out(usb3, a_dev); /* for A-Peripheral or forced B-device mode */ - if ((!host && a_dev) || - (usb3->workaround_for_vbus && usb3->forced_b_device)) + if ((!host && a_dev) || usb3->start_to_connect) usb3_connect(usb3); spin_unlock_irqrestore(&usb3->lock, flags); } @@ -2432,7 +2433,11 @@ static ssize_t renesas_usb3_b_device_write(struct file *file, if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) return -EFAULT;
- if (!strncmp(buf, "1", 1)) + usb3->start_to_connect = false; + if (usb3->workaround_for_vbus && usb3->forced_b_device && + !strncmp(buf, "2", 1)) + usb3->start_to_connect = true; + else if (!strncmp(buf, "1", 1)) usb3->forced_b_device = true; else usb3->forced_b_device = false; @@ -2440,7 +2445,7 @@ static ssize_t renesas_usb3_b_device_write(struct file *file, if (usb3->workaround_for_vbus) usb3_disconnect(usb3);
- /* Let this driver call usb3_connect() anyway */ + /* Let this driver call usb3_connect() if needed */ usb3_check_id(usb3);
return count;