5.10-stable patches

added patches:
	usb-serial-cp210x-fix-dropped-characters-with-cp2102.patch

diff --git a/queue-5.10/series b/queue-5.10/series
index e045e50d81b28a1ed9a82cc3d2667dbc685b04df..258aba6bf77d41b28db440e16d9f3dd176e8c213 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -98,3 +98,4 @@ spi-fix-tegra20-build-with-config_pm-n.patch
 edac-synopsys-fix-wrong-value-type-assignment-for-edac_mode.patch
 edac-dmc520-assign-the-proper-type-to-dimm-edac_mode.patch
 thermal-drivers-int340x-do-not-set-a-wrong-tcc-offset-on-resume.patch
+usb-serial-cp210x-fix-dropped-characters-with-cp2102.patch

diff --git a/queue-5.10/usb-serial-cp210x-fix-dropped-characters-with-cp2102.patch b/queue-5.10/usb-serial-cp210x-fix-dropped-characters-with-cp2102.patch
new file mode 100644 (file)
index 0000000..bfeafdd
--- /dev/null
+++ b/queue-5.10/usb-serial-cp210x-fix-dropped-characters-with-cp2102.patch
@@ -0,0 +1,124 @@
+From c32dfec6c1c36bbbcd5d33e949d99aeb215877ec Mon Sep 17 00:00:00 2001
+From: Johan Hovold <johan@kernel.org>
+Date: Wed, 22 Sep 2021 13:30:59 +0200
+Subject: USB: serial: cp210x: fix dropped characters with CP2102
+
+From: Johan Hovold <johan@kernel.org>
+
+commit c32dfec6c1c36bbbcd5d33e949d99aeb215877ec upstream.
+
+Some CP2102 do not support event-insertion mode but return no error when
+attempting to enable it.
+
+This means that any event escape characters in the input stream will not
+be escaped by the device and consequently regular data may be
+interpreted as escape sequences and be removed from the stream by the
+driver.
+
+The reporter's device has batch number DCL00X etched into it and as
+discovered by the SHA2017 Badge team, counterfeit devices with that
+marking can be detected by sending malformed vendor requests. [1][2]
+
+Tests confirm that the possibly counterfeit CP2102 returns a single byte
+in response to a malformed two-byte part-number request, while an
+original CP2102 returns two bytes. Assume that every CP2102 that behaves
+this way also does not support event-insertion mode (e.g. cannot report
+parity errors).
+
+[1] https://mobile.twitter.com/sha2017badge/status/1167902087289532418
+[2] https://hackaday.com/2017/08/14/hands-on-with-the-shacamp-2017-badge/#comment-3903376
+
+Reported-by: Malte Di Donato <malte@neo-soft.org>
+Tested-by: Malte Di Donato <malte@neo-soft.org>
+Fixes: a7207e9835a4 ("USB: serial: cp210x: add support for line-status events")
+Cc: stable@vger.kernel.org     # 5.9
+Link: https://lore.kernel.org/r/20210922113100.20888-1-johan@kernel.org
+Signed-off-by: Johan Hovold <johan@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/usb/serial/cp210x.c |   46 ++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 46 insertions(+)
+
+--- a/drivers/usb/serial/cp210x.c
++++ b/drivers/usb/serial/cp210x.c
+@@ -261,6 +261,7 @@ struct cp210x_serial_private {
+       speed_t                 min_speed;
+       speed_t                 max_speed;
+       bool                    use_actual_rate;
++      bool                    no_event_mode;
+ };
+ 
+ enum cp210x_event_state {
+@@ -1332,12 +1333,16 @@ static void cp210x_change_speed(struct t
+ 
+ static void cp210x_enable_event_mode(struct usb_serial_port *port)
+ {
++      struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
+       struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+       int ret;
+ 
+       if (port_priv->event_mode)
+               return;
+ 
++      if (priv->no_event_mode)
++              return;
++
+       port_priv->event_state = ES_DATA;
+       port_priv->event_mode = true;
+ 
+@@ -2087,6 +2092,46 @@ static void cp210x_init_max_speed(struct
+       priv->use_actual_rate = use_actual_rate;
+ }
+ 
++static void cp2102_determine_quirks(struct usb_serial *serial)
++{
++      struct cp210x_serial_private *priv = usb_get_serial_data(serial);
++      u8 *buf;
++      int ret;
++
++      buf = kmalloc(2, GFP_KERNEL);
++      if (!buf)
++              return;
++      /*
++       * Some (possibly counterfeit) CP2102 do not support event-insertion
++       * mode and respond differently to malformed vendor requests.
++       * Specifically, they return one instead of two bytes when sent a
++       * two-byte part-number request.
++       */
++      ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
++                      CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
++                      CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
++      if (ret == 1) {
++              dev_dbg(&serial->interface->dev,
++                              "device does not support event-insertion mode\n");
++              priv->no_event_mode = true;
++      }
++
++      kfree(buf);
++}
++
++static void cp210x_determine_quirks(struct usb_serial *serial)
++{
++      struct cp210x_serial_private *priv = usb_get_serial_data(serial);
++
++      switch (priv->partnum) {
++      case CP210X_PARTNUM_CP2102:
++              cp2102_determine_quirks(serial);
++              break;
++      default:
++              break;
++      }
++}
++
+ static int cp210x_attach(struct usb_serial *serial)
+ {
+       int result;
+@@ -2107,6 +2152,7 @@ static int cp210x_attach(struct usb_seri
+ 
+       usb_set_serial_data(serial, priv);
+ 
++      cp210x_determine_quirks(serial);
+       cp210x_init_max_speed(serial);
+ 
+       result = cp210x_gpio_init(serial);