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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
USB: serial: ch341: change initial line-control settings
Some CH340 devices appear unable to change the initial LCR settings, so
set a sane 8N1 default during probe to enable basic support for such
devices.
Also drop a redundant LCR read during device initialisation.
Signed-off-by: Johan Hovold <johan@kernel.org>
+5
-9
+5
-9
drivers/usb/serial/ch341.c
+5
-9
drivers/usb/serial/ch341.c
···
238
238
if (r < 0)
239
239
goto out;
240
240
241
-
/* expect two bytes 0x56 0x00 */
242
-
r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
243
-
if (r < 0)
244
-
goto out;
245
-
246
-
r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
247
-
if (r < 0)
248
-
goto out;
249
-
250
241
r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
251
242
if (r < 0)
252
243
goto out;
···
259
268
260
269
spin_lock_init(&priv->lock);
261
270
priv->baud_rate = DEFAULT_BAUD_RATE;
271
+
/*
272
+
* Some CH340 devices appear unable to change the initial LCR
273
+
* settings, so set a sane 8N1 default.
274
+
*/
275
+
priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
262
276
263
277
r = ch341_configure(port->serial->dev, priv);
264
278
if (r < 0)