4.14-stable review patch. If anyone has any objections, please let me know.
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From: Douglas Anderson dianders@chromium.org
[ Upstream commit a5feba71ec9c14a54c3babdc732c5b6866d8ee43 ]
According to the comment next to USB_CTRL_GET_TIMEOUT and USB_CTRL_SET_TIMEOUT, although sending/receiving control messages is usually quite fast, the spec allows them to take up to 5 seconds. Let's increase the timeout in the Realtek driver from 500ms to 5000ms (using the #defines) to account for this.
This is not just a theoretical change. The need for the longer timeout was seen in testing. Specifically, if you drop a sc7180-trogdor based Chromebook into the kdb debugger and then "go" again after sitting in the debugger for a while, the next USB control message takes a long time. Out of ~40 tests the slowest USB control message was 4.5 seconds.
While dropping into kdb is not exactly an end-user scenario, the above is similar to what could happen due to an temporary interrupt storm, what could happen if there was a host controller (HW or SW) issue, or what could happen if the Realtek device got into a confused state and needed time to recover.
This change is fairly critical since the r8152 driver in Linux doesn't expect register reads/writes (which are backed by USB control messages) to fail.
Fixes: ac718b69301c ("net/usb: new driver for RTL8152") Suggested-by: Hayes Wang hayeswang@realtek.com Signed-off-by: Douglas Anderson dianders@chromium.org Reviewed-by: Grant Grundler grundler@chromium.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/r8152.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index d17d125a34540..a0b40bdbdd84f 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -786,7 +786,7 @@ int get_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data)
ret = usb_control_msg(tp->udev, usb_rcvctrlpipe(tp->udev, 0), RTL8152_REQ_GET_REGS, RTL8152_REQT_READ, - value, index, tmp, size, 500); + value, index, tmp, size, USB_CTRL_GET_TIMEOUT); if (ret < 0) memset(data, 0xff, size); else @@ -809,7 +809,7 @@ int set_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data)
ret = usb_control_msg(tp->udev, usb_sndctrlpipe(tp->udev, 0), RTL8152_REQ_SET_REGS, RTL8152_REQT_WRITE, - value, index, tmp, size, 500); + value, index, tmp, size, USB_CTRL_SET_TIMEOUT);
kfree(tmp);
@@ -5084,7 +5084,8 @@ static u8 rtl_get_version(struct usb_interface *intf)
ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), RTL8152_REQ_GET_REGS, RTL8152_REQT_READ, - PLA_TCR0, MCU_TYPE_PLA, tmp, sizeof(*tmp), 500); + PLA_TCR0, MCU_TYPE_PLA, tmp, sizeof(*tmp), + USB_CTRL_GET_TIMEOUT); if (ret > 0) ocp_data = (__le32_to_cpu(*tmp) >> 16) & VERSION_MASK;