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 184b458820a313cb0412b8ed13e0981976b3d8c1..6ff1e725f404f2d09a0b2ee6c3bf85a2f3a472d1 100644 (file)
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1000,7 +1000,7 @@ 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 8f385fbe5a0ebcf9c1a7a6ff6c986893548b4209..1c31f26ccc7a5eada9a768c9c29cf61220bc0060 100644 (file)
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -248,6 +248,9 @@ 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
+
 /*
  * Define bandwidth thresholds that cause the underlying Core 2X interconnect
  * clock to run at the named frequency. These baseline values are recommended