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serial: qcom_geni_serial: To correct QUP Version detection logic 

commit c9ca43d42e upstream.

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

Commit ce73460054 ("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: ce73460054 ("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>
5.4-rM2-2.2.x-imx-squashed
Paras Sharma 2020-09-30 11:35:26 +05:30 committed by Greg Kroah-Hartman
parent c274d1f8ba
commit 44ef3b63c7
2 changed files with 4 additions and 1 deletions
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2
drivers/tty/serial/qcom_geni_serial.c
View File

@ -970,7 +970,7 @@ 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);

3
include/linux/qcom-geni-se.h
View File

@ -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);