[PATCH 4.19 59/97] tty: serial: qcom_geni_serial: Fix RX cancel command failure

Greg Kroah-Hartman
2020-02-27T14:07:02Z

From: satya priya <skakit@codeaurora.org>

[ Upstream commit 679aac5ead2f18d223554a52b543e1195e181811 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/qcom_geni_serial.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 4182129925dec..4458419f053b6 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -121,6 +121,7 @@ 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,
@@ -614,7 +615,7 @@ 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);
@@ -630,10 +631,19 @@ 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);
}
--
2.20.1