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path: root/drivers/usb/serial/ch341.c
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Diffstat (limited to 'drivers/usb/serial/ch341.c')
-rw-r--r--drivers/usb/serial/ch341.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index d3f420f3a083..c5ecdcd51ffc 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -205,6 +205,16 @@ static int ch341_get_divisor(speed_t speed)
16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1)))
div++;
+ /*
+ * Prefer lower base clock (fact = 0) if even divisor.
+ *
+ * Note that this makes the receiver more tolerant to errors.
+ */
+ if (fact == 1 && div % 2 == 0) {
+ div /= 2;
+ fact = 0;
+ }
+
return (0x100 - div) << 8 | fact << 2 | ps;
}