[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v3 4/4] xen/drivers/char: fix exynos4210 IRQ registration failure propagation


  • To: "Orzel, Michal" <michal.orzel@xxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Oleksandr_Tyshchenko@xxxxxxxx
  • From: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
  • Date: Thu, 23 Apr 2026 11:26:49 +0300
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=epam.com; dmarc=pass action=none header.from=epam.com; dkim=pass header.d=epam.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=avfNGRJegDCY911DjaNTuGaKuo9exjiT/NHVp4i7TgQ=; b=Yxo4UfOJkLhQGc9wLcKrKJ3NASqLGCg71WLjC8CGk7WOlyG74jdtzSRe+IOG9hxkge4FD9+0cxsYAlqEVd6cuo+NAV2sSnBaoRBYgBCxN/GDREL1TzdsCDpC0cdFBGcyCr1E+MCQXPBoQqdhWQKKqfvNE8hAluewr+wvB73lwA5zdMMBDSU068Da+NHx97NXIESZv+o4aBLEYlsGZlnOGlrdAKV190LVJtko91y3rPEAelgR9cw0RLjOJBvEhvPt86ql0yKW6t1TSZy+eL2rJcVPbiY+fFTZuJ9IxpNt7/maPSIOkeHvQfpdR+9QclC90S+aAjBuQymYZAKCXKJtRw==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=uAS3rkNxhnQu0q+oqxpqfJGIZe1EotiiWb+V4n88QLmNOtRd6aNvgbjqSP56iVK0t1WRBNp/MTO9HBmky/5jei8l/5cGtvZDVjH89iTXOlHS0T7YlGdIccOSUSAVqycJG0MDivjKJAnn1UizIEIWsW8PLnKHkZY6PTWg24oN7TgaStGifPMpE3zP8jbulWpSIBGK0vkdOFL7AJxX3l5DZ1qdIgCarbyJTl36RuqI6RkfKFFCJQcIOx7bjjzOhNExrVBjc6Z33IDktG6vxLDI9VjlBg6cwTS1LH4bZAYrKOwPtkAj6hGEUGQrTuF5cZ9GJM0KtFm5iU7AVWcvD984Mg==
  • Authentication-results: eu.smtp.expurgate.cloud; dkim=pass header.s=selector1 header.d=epam.com header.i="@epam.com" header.h="From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck"
  • Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=epam.com;
  • Cc: Bertrand Marquis <bertrand.marquis@xxxxxxx>, Julien Grall <julien@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
  • Delivery-date: Thu, 23 Apr 2026 08:27:02 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

Hi Michal, Oleksandr

Thank you for the fast review. Well, I don't know why the commit differs :). I haven't copied it, just wrote from scratch.

I see that overall it looks good. I can post v4 with nits fixed from you and Oleksandr, or they will be fixed on commit.

Which way is more convenient for you?

--

Oleksii.

On 22/04/2026 14:33, Orzel, Michal wrote:

On 22/04/2026 11:33, Oleksii Moisieiev wrote:
In exynos4210_uart_init_postirq(), when setup_irq() returns an error
the failure was only logged via dprintk() and execution continued,
unconditionally clearing UINTM and setting UMCON_INT_EN. This enabled
receive and transmit interrupt lines with no handler registered. On
platforms where the GIC receives these asserted lines, the result is
either repeated spurious-interrupt warnings or an unhandled interrupt
fault.

Add an early return in the setup_irq() error branch so that the
interrupt-enable writes to UINTM and UMCON are skipped when IRQ
registration fails.

Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
---

Changes in v3:
- skip clearing pending interrupts if setup_irq was failed because
according to the 13.4.1.13 of the RM: it must be cleared after
cleaning interrupt pending in INTC.

  xen/drivers/char/exynos4210-uart.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/xen/drivers/char/exynos4210-uart.c 
b/xen/drivers/char/exynos4210-uart.c
index 58901df554..2e5860ea2b 100644
--- a/xen/drivers/char/exynos4210-uart.c
+++ b/xen/drivers/char/exynos4210-uart.c
@@ -199,8 +199,12 @@ static void __init exynos4210_uart_init_postirq(struct 
serial_port *port)
      uart->irqaction.dev_id  = port;
if ( (rc = setup_irq(uart->irq, 0, &uart->irqaction)) != 0 )
+    {
          dprintk(XENLOG_ERR, "Failed to allocated exynos4210_uart IRQ %d\n",
                  uart->irq);
+        /* Don't enable interrupts if irq setup was failed */
NIT: Not sure why this comment differs from one patch to another. Preferably
they should all be the same.

Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>

~Michal




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.