svn commit: r335620 - stable/11/sys/dev/usb/serial

[Andriy Gapon]

Author: avg
Date: Mon Jun 25 08:50:06 2018
New Revision: 335620
URL: https://svnweb.freebsd.org/changeset/base/335620

Log:
  MFC r333999: uchcom: add a hardware configuration tweak seen in Linux code

Modified:
  stable/11/sys/dev/usb/serial/uchcom.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/dev/usb/serial/uchcom.c
==============================================================================
--- stable/11/sys/dev/usb/serial/uchcom.c	Mon Jun 25 08:49:13 2018	(r335619)
+++ stable/11/sys/dev/usb/serial/uchcom.c	Mon Jun 25 08:50:06 2018	(r335620)
@@ -616,8 +616,12 @@ uchcom_set_baudrate(struct uchcom_softc *sc, uint32_t 
 	if (uchcom_calc_divider_settings(&dv, rate))
 		return;
 
+	/*
+	 * According to linux code we need to set bit 7 of UCHCOM_REG_BPS_PRE,
+	 * otherwise the chip will buffer data.
+	 */
 	uchcom_write_reg(sc,
-	    UCHCOM_REG_BPS_PRE, dv.dv_prescaler,
+	    UCHCOM_REG_BPS_PRE, dv.dv_prescaler | 0x80,
 	    UCHCOM_REG_BPS_DIV, dv.dv_div);
 	uchcom_write_reg(sc,
 	    UCHCOM_REG_BPS_MOD, dv.dv_mod,