The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024070339-simile-village-6731@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 Mon Sep 17 00:00:00 2001 From: Udit Kumar u-kumar1@ti.com Date: Tue, 25 Jun 2024 21:37:25 +0530 Subject: [PATCH] serial: 8250_omap: Fix Errata i2310 with RX FIFO level check

Errata i2310[0] says, Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts.

Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") which added the workaround but missed ensuring RX FIFO is really empty before applying the errata workaround as recommended in the errata text. Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for workaround to take effect.

[0] https://www.ti.com/lit/pdf/sprz536 page 23

Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") Cc: stable@vger.kernel.org Reported-by: Vignesh Raghavendra vigneshr@ti.com Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/ Signed-off-by: Udit Kumar u-kumar1@ti.com Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index ddac0a13cf84..1af9aed99c65 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -672,7 +672,8 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) * https://www.ti.com/lit/pdf/sprz536 */ if (priv->habit & UART_RX_TIMEOUT_QUIRK && - (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) { + (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT && + serial_port_in(port, UART_OMAP_RX_LVL) == 0) { unsigned char efr2, timeout_h, timeout_l;

efr2 = serial_in(up, UART_OMAP_EFR2);