2 files changed, 132 insertions, 0 deletions

diff --git a/meta-yocto-bsp/recipes-kernel/linux/files/0001-Revert-serial-8250_omap-Drop-pm_runtime_irq_safe.patch b/meta-yocto-bsp/recipes-kernel/linux/files/0001-Revert-serial-8250_omap-Drop-pm_runtime_irq_safe.patch
new file mode 100644
index 0000000000..8837dd2346
--- /dev/null
+++ b/meta-yocto-bsp/recipes-kernel/linux/files/0001-Revert-serial-8250_omap-Drop-pm_runtime_irq_safe.patch
@@ -0,0 +1,130 @@
+From cc255f5132cf39e9154340cf58780f8c763c6481 Mon Sep 17 00:00:00 2001
+From: Ross Burton <ross.burton@arm.com>
+Date: Thu, 23 Jan 2025 17:06:08 +0000
+Subject: [PATCH] Revert "serial: 8250_omap: Drop pm_runtime_irq_safe()"
+
+This reverts commit 8700a7ea5519fb0b3bad2362adfeac358c2119ce.
+
+Upstream-Status: Inappropriate
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+---
+ drivers/tty/serial/8250/8250_omap.c | 29 ++++++++---------------------
+ 1 file changed, 8 insertions(+), 21 deletions(-)
+
+diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
+index 0dd68bdbfbcf7..db24d7d1dcb67 100644
+--- a/drivers/tty/serial/8250/8250_omap.c
++++ b/drivers/tty/serial/8250/8250_omap.c
+@@ -8,7 +8,6 @@
+  *
+  */
+ 
+-#include <linux/atomic.h>
+ #include <linux/clk.h>
+ #include <linux/device.h>
+ #include <linux/io.h>
+@@ -134,7 +133,6 @@ struct omap8250_priv {
+ 
+        u8 tx_trigger;
+        u8 rx_trigger;
+-       atomic_t active;
+        bool is_suspending;
+        int wakeirq;
+        u32 latency;
+@@ -636,23 +634,14 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
+        unsigned int iir, lsr;
+        int ret;
+ 
+-       pm_runtime_get_noresume(port->dev);
+-
+-       /* Shallow idle state wake-up to an IO interrupt? */
+-       if (atomic_add_unless(&priv->active, 1, 1)) {
+-               priv->latency = priv->calc_latency;
+-               schedule_work(&priv->qos_work);
+-       }
+-
+ #ifdef CONFIG_SERIAL_8250_DMA
+        if (up->dma) {
+                ret = omap_8250_dma_handle_irq(port);
+-               pm_runtime_mark_last_busy(port->dev);
+-               pm_runtime_put(port->dev);
+                return IRQ_RETVAL(ret);
+        }
+ #endif
+ 
++       serial8250_rpm_get(up);
+        lsr = serial_port_in(port, UART_LSR);
+        iir = serial_port_in(port, UART_IIR);
+        ret = serial8250_handle_irq(port, iir);
+@@ -701,8 +690,7 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
+                schedule_delayed_work(&up->overrun_backoff, delay);
+        }
+ 
+-       pm_runtime_mark_last_busy(port->dev);
+-       pm_runtime_put(port->dev);
++       serial8250_rpm_put(up);
+ 
+        return IRQ_RETVAL(ret);
+ }
+@@ -1314,8 +1302,11 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
+        u16 status;
+        u8 iir;
+ 
++       serial8250_rpm_get(up);
++
+        iir = serial_port_in(port, UART_IIR);
+        if (iir & UART_IIR_NO_INT) {
++               serial8250_rpm_put(up);
+                return IRQ_HANDLED;
+        }
+ 
+@@ -1348,6 +1339,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
+ 
+        uart_unlock_and_check_sysrq(port);
+ 
++       serial8250_rpm_put(up);
+        return 1;
+ }
+ 
+@@ -1539,6 +1531,8 @@ static int omap8250_probe(struct platform_device *pdev)
+        if (!of_get_available_child_count(pdev->dev.of_node))
+                pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
+ 
++       pm_runtime_irq_safe(&pdev->dev);
++
+        pm_runtime_get_sync(&pdev->dev);
+ 
+        omap_serial_fill_features_erratas(&up, priv);
+@@ -1776,7 +1770,6 @@ static int omap8250_runtime_suspend(struct device *dev)
+ 
+        priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+        schedule_work(&priv->qos_work);
+-       atomic_set(&priv->active, 0);
+ 
+        return 0;
+ }
+@@ -1786,10 +1779,6 @@ static int omap8250_runtime_resume(struct device *dev)
+        struct omap8250_priv *priv = dev_get_drvdata(dev);
+        struct uart_8250_port *up = NULL;
+ 
+-       /* Did the hardware wake to a device IO interrupt before a wakeirq? */
+-       if (atomic_read(&priv->active))
+-               return 0;
+-
+        if (priv->line >= 0)
+                up = serial8250_get_port(priv->line);
+ 
+@@ -1805,10 +1794,8 @@ static int omap8250_runtime_resume(struct device *dev)
+                uart_port_unlock_irq(&up->port);
+        }
+ 
+-       atomic_set(&priv->active, 1);
+        priv->latency = priv->calc_latency;
+        schedule_work(&priv->qos_work);
+-
+        return 0;
+ }
+ 
+-- 
+2.43.0
+
diff --git a/meta-yocto-bsp/recipes-kernel/linux/linux-yocto_6.12.bbappend b/meta-yocto-bsp/recipes-kernel/linux/linux-yocto_6.12.bbappend
index 1ffd2194d9..831cb556be 100644
--- a/meta-yocto-bsp/recipes-kernel/linux/linux-yocto_6.12.bbappend
+++ b/meta-yocto-bsp/recipes-kernel/linux/linux-yocto_6.12.bbappend
@@ -7,3 +7,5 @@ KMACHINE:beaglebone-yocto ?= "beaglebone"
 KMACHINE:genericx86 ?= "common-pc"
 KMACHINE:genericx86-64 ?= "common-pc-64"
 
+FILESEXTRAPATHS:prepend:genericarm64 := "${THISDIR}/files:"
+SRC_URI:append:genericarm64 = " file://0001-Revert-serial-8250_omap-Drop-pm_runtime_irq_safe.patch"