On 6/14/2024 1:58 PM, Ilpo Järvinen wrote:
On Fri, 14 Jun 2024, Udit Kumar wrote:
As per Errata i2310[0], Erroneous timeout can be triggered,
if this Erroneous interrupt is not cleared then it may leads
to strom of interrupts, therefore apply Errata i2310 solution.
[0] https://www.ti.com/lit/pdf/sprz536 page 23
Signed-off-by: Udit Kumar <u-kumar1@xxxxxx>
---
drivers/tty/serial/8250/8250_omap.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 170639d12b2a..38eb639f78d3 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -115,6 +115,10 @@
/* RX FIFO occupancy indicator */
#define UART_OMAP_RX_LVL 0x19
+/* Timeout Low and High */
+#define UART_OMAP_TO_L 0x26
+#define UART_OMAP_TO_H 0x27
+
/*
* Copy of the genpd flags for the console.
* Only used if console suspend is disabled
@@ -663,13 +667,24 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
/*
* On K3 SoCs, it is observed that RX TIMEOUT is signalled after
- * FIFO has been drained, in which case a dummy read of RX FIFO
- * is required to clear RX TIMEOUT condition.
+ * FIFO has been drained or erroneously.
+ * So apply solution of Errata i2310 as mentioned in
+ * https://www.ti.com/lit/pdf/sprz536
*/
if (priv->habit & UART_RX_TIMEOUT_QUIRK &&
- (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT &&
- serial_port_in(port, UART_OMAP_RX_LVL) == 0) {
- serial_port_in(port, UART_RX);
+ (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) {
+ unsigned char efr2, timeout_h, timeout_l;
+
+ efr2 = serial_in(up, UART_OMAP_EFR2);
+ timeout_h = serial_in(up, UART_OMAP_TO_H);
+ timeout_l = serial_in(up, UART_OMAP_TO_L);
+ serial_out(up, UART_OMAP_TO_H, 0xFF);
+ serial_out(up, UART_OMAP_TO_L, 0xFF);
+ serial_out(up, UART_OMAP_EFR2, 0x1);
Eh, this doesn't match the workaround in the errata???
Also, don't use literals but name the bits with defines (for the correct
bit there's probably a pre-existing define but it's not named as good as
it could be, I'd say it should be named as
UART_OMAP_EFR2_TIMEOUT_PERIODIC).
Thanks, will address in v2.
+ serial_in(up, UART_IIR);
+ serial_out(up, UART_OMAP_EFR2, efr2);
+ serial_out(up, UART_OMAP_TO_H, timeout_h);
+ serial_out(up, UART_OMAP_TO_L, timeout_l);
