serial: qcom_geni_serial: To correct QUP Version detection logic

commit c9ca43d42ed8d5fd635d327a664ed1d8579eb2af upstream.

For QUP IP versions 2.5 and above the oversampling rate is
halved from 32 to 16.

Commit ce734600545f ("tty: serial: qcom_geni_serial: Update
the oversampling rate") is pushed to handle this scenario.
But the existing logic is failing to classify QUP Version 3.0
into the correct group ( 2.5 and above).

As result Serial Engine clocks are not configured properly for
baud rate and garbage data is sampled to FIFOs from the line.

So, fix the logic to detect QUP with versions 2.5 and above.

Fixes: ce734600545f ("tty: serial: qcom_geni_serial: Update the oversampling rate")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Paras Sharma <parashar@codeaurora.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
Link: https://lore.kernel.org/r/1601445926-23673-1-git-send-email-parashar@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index ffdf6da016c21b965c5b387a8e98bbd682972320..2bb800ca5f0ca2d5e2af209006891b609b5a1c7e 100644 (file)
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -954,7 +954,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
        sampling_rate = UART_OVERSAMPLING;
        /* Sampling rate is halved for IP versions >= 2.5 */
        ver = geni_se_get_qup_hw_version(&port->se);
-       if (GENI_SE_VERSION_MAJOR(ver) >= 2 && GENI_SE_VERSION_MINOR(ver) >= 5)
+       if (ver >= QUP_SE_VERSION_2_5)
                sampling_rate /= 2;
 
        clk_rate = get_clk_div_rate(baud, sampling_rate, &clk_div);

diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h
index dd464943f717a476964000348e87103b2063b6bb..5b90eff50bf6eb758a08b3fc50abd97fdaa58620 100644 (file)
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -229,6 +229,9 @@ struct geni_se {
 #define GENI_SE_VERSION_MINOR(ver) ((ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT)
 #define GENI_SE_VERSION_STEP(ver) (ver & HW_VER_STEP_MASK)
 
+/* QUP SE VERSION value for major number 2 and minor number 5 */
+#define QUP_SE_VERSION_2_5                  0x20050000
+
 #if IS_ENABLED(CONFIG_QCOM_GENI_SE)
 
 u32 geni_se_get_qup_hw_version(struct geni_se *se);