From patchwork Tue May 30 16:35:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: dann frazier X-Patchwork-Id: 768718 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3wcfP72fNKz9s2P; Wed, 31 May 2017 02:35:55 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1dFk7Z-00089y-JV; Tue, 30 May 2017 16:35:49 +0000 Received: from complete.lackof.org ([198.49.126.79]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1dFk7U-00089j-Rz for kernel-team@lists.ubuntu.com; Tue, 30 May 2017 16:35:44 +0000 Received: from localhost (c-107-2-141-92.hsd1.co.comcast.net [107.2.141.92]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by complete.lackof.org (Postfix) with ESMTPSA id 9CC4233E00B7 for ; Tue, 30 May 2017 10:35:40 -0600 (MDT) Date: Tue, 30 May 2017 10:35:40 -0600 From: dann frazier To: kernel-team@lists.ubuntu.com Subject: [PATCH][SRU Zesty] drivers/tty: 8250: only call fintek_8250_probe when doing port I/O Message-ID: <20170530163540.2gavxupcgdt7rwhr@xps13.dannf> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170306 (1.8.0) X-Spam-Status: No, score=0.0 required=5.0 tests=UNPARSEABLE_RELAY autolearn=unavailable version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on complete.lackof.org X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Ard Biesheuvel BugLink: https://bugs.launchpad.net/bugs/1692548 Commit fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base") modified the probing logic for PNP0501 devices, to remove a collision between the generic 16550A driver and the Fintek driver, which reused the same ACPI _HID. The Fintek device probe is now incorporated into the common 8250 probe path, and gets called for all discovered 16550A compatible devices, including ones that are MMIO mapped rather than IO mapped. However, the Fintek driver assumes the port base is a I/O address, and proceeds to probe some arbitrary offsets above it. This is generally a wrong thing to do, but on ARM systems (having no native port I/O), this may result in faulting accesses of completely unrelated MMIO regions in the PCI I/O space. Given that this is at serial probe time, this results in hard to diagnose crashes at boot. So let's restrict the Fintek probe to devices that we know are using port I/O in the first place. Fixes: fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base") Suggested-by: Arnd Bergmann Reviewed-by: Ricardo Ribalda Signed-off-by: Ard Biesheuvel Cc: stable Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 4c4fc90964b1cf205a67df566cc82ea1731bcb00) Signed-off-by: dann frazier Acked-by: Colin Ian King Acked-by: Seth Forshee --- drivers/tty/serial/8250/8250_port.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index c13fec451d03..331bbe38e34b 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1322,7 +1322,7 @@ static void autoconfig(struct uart_8250_port *up) /* * Check if the device is a Fintek F81216A */ - if (port->type == PORT_16550A) + if (port->type == PORT_16550A && port->iotype == UPIO_PORT) fintek_8250_probe(up); if (up->capabilities != old_capabilities) {