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The following commit(s) were added to refs/heads/master by this push:
new 5594c2e887 imx9/lpuart: Fix race condition / regression in imx9_txint
5594c2e887 is described below
commit 5594c2e8875730f2f65b9fab57806e4c3c046379
Author: Jukka Laitinen <jukka.laiti...@tii.ae>
AuthorDate: Tue Jul 1 14:44:42 2025 +0300
imx9/lpuart: Fix race condition / regression in imx9_txint
Commit 83a119160 fixed SMP by removing call to uart_xmitchars from inside
spinlock.
This only works for SMP, since uart_xmitchars has a lock only in SMP. In a
single
core configuration the function can be called in parallel from the interrupt
handler and from the imx9_txint.
Fix this by filling the uart buffers already before enabling the
interrupt, this way it is not possible to get the function called in
parallel
for the same device.
Signed-off-by: Jukka Laitinen <jukka.laiti...@tii.ae>
---
arch/arm64/src/imx9/imx9_lpuart.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/src/imx9/imx9_lpuart.c
b/arch/arm64/src/imx9/imx9_lpuart.c
index d656de14f8..497d73ca5c 100644
--- a/arch/arm64/src/imx9/imx9_lpuart.c
+++ b/arch/arm64/src/imx9/imx9_lpuart.c
@@ -2340,6 +2340,13 @@ static void imx9_txint(struct uart_dev_s *dev, bool
enable)
irqstate_t flags;
uint32_t regval;
+#ifndef CONFIG_SUPPRESS_SERIAL_INTS
+ if (enable)
+ {
+ uart_xmitchars(dev);
+ }
+#endif
+
/* Enable interrupt for TX complete */
flags = spin_lock_irqsave(&priv->lock);
@@ -2359,13 +2366,6 @@ static void imx9_txint(struct uart_dev_s *dev, bool
enable)
regval |= priv->ie;
imx9_serialout(priv, IMX9_LPUART_CTRL_OFFSET, regval);
spin_unlock_irqrestore(&priv->lock, flags);
-
-#ifndef CONFIG_SUPPRESS_SERIAL_INTS
- if (enable)
- {
- uart_xmitchars(dev);
- }
-#endif
}
#endif
