aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/ch341.c
diff options
context:
space:
mode:
authorPaolo Bonzini <pbonzini@redhat.com>2022-09-23 10:06:08 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2022-09-23 10:06:08 -0400
commit69604fe76e58c9d195e48b41d019b07fc27ce9d7 (patch)
treec9d1e7cfe406a8f168c3aceaf989eea0275d3045 /drivers/usb/serial/ch341.c
parent50b2d49bafa16e6311ab2da82f5aafc5f9ada99b (diff)
parent189e7d876e48d7c791fe1c9c01516f70f5621a9f (diff)
Merge tag 'kvm-s390-master-6.0-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
More pci fixes Fix for a code analyser warning
Diffstat (limited to 'drivers/usb/serial/ch341.c')
-rw-r--r--drivers/usb/serial/ch341.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 2798fca71261..af01a462cc43 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -97,7 +97,10 @@ struct ch341_private {
u8 mcr;
u8 msr;
u8 lcr;
+
unsigned long quirks;
+ u8 version;
+
unsigned long break_end;
};
@@ -250,8 +253,12 @@ static int ch341_set_baudrate_lcr(struct usb_device *dev,
/*
* CH341A buffers data until a full endpoint-size packet (32 bytes)
* has been received unless bit 7 is set.
+ *
+ * At least one device with version 0x27 appears to have this bit
+ * inverted.
*/
- val |= BIT(7);
+ if (priv->version > 0x27)
+ val |= BIT(7);
r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER,
@@ -265,6 +272,9 @@ static int ch341_set_baudrate_lcr(struct usb_device *dev,
* (stop bits, parity and word length). Version 0x30 and above use
* CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero.
*/
+ if (priv->version < 0x30)
+ return 0;
+
r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr);
if (r)
@@ -308,7 +318,9 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
if (r)
return r;
- dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
+
+ priv->version = buffer[0];
+ dev_dbg(&dev->dev, "Chip version: 0x%02x\n", priv->version);
r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
if (r < 0)