tty: serial: qcom_geni_serial: Fix RX cancel command failure

RX cancel command fails when BT is switched on and off multiple times.

To handle this, poll for the cancel bit in SE_GENI_S_IRQ_STATUS register
instead of SE_GENI_S_CMD_CTRL_REG.

As per the HPG update, handle the RX last bit after cancel command
and flush out the RX FIFO buffer.

Signed-off-by: satya priya <skakit@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1581415982-8793-1-git-send-email-skakit@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 191abb1..0bd1684 100644 (file)
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -129,6 +129,7 @@ static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop);
 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop);
 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *port);
 static void qcom_geni_serial_stop_rx(struct uart_port *uport);
+static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop);
 
 static const unsigned long root_freq[] = {7372800, 14745600, 19200000, 29491200,
                                        32000000, 48000000, 64000000, 80000000,
@@ -599,7 +600,7 @@ static void qcom_geni_serial_stop_rx(struct uart_port *uport)
        u32 irq_en;
        u32 status;
        struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
-       u32 irq_clear = S_CMD_DONE_EN;
+       u32 s_irq_status;
 
        irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
        irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
@@ -615,10 +616,19 @@ static void qcom_geni_serial_stop_rx(struct uart_port *uport)
                return;
 
        geni_se_cancel_s_cmd(&port->se);
-       qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
-                                       S_GENI_CMD_CANCEL, false);
+       qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
+                                       S_CMD_CANCEL_EN, true);
+       /*
+        * If timeout occurs secondary engine remains active
+        * and Abort sequence is executed.
+        */
+       s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
+       /* Flush the Rx buffer */
+       if (s_irq_status & S_RX_FIFO_LAST_EN)
+               qcom_geni_serial_handle_rx(uport, true);
+       writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
+
        status = readl(uport->membase + SE_GENI_STATUS);
-       writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
        if (status & S_GENI_CMD_ACTIVE)
                qcom_geni_serial_abort_rx(uport);
 }