Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757364AbcKCLji (ORCPT ); Thu, 3 Nov 2016 07:39:38 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:47049 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756737AbcKCLjg (ORCPT ); Thu, 3 Nov 2016 07:39:36 -0400 Date: Thu, 3 Nov 2016 17:09:27 +0530 From: Sandeep Jain To: , CC: , , Vladimir Zapolskiy Subject: Re: [PATCH v1 1/2] mtd: m25p80: lock module while used Message-ID: <20161103113926.GB4873@mentor.com> References: <1470320194-9602-1-git-send-email-Sandeep_Jain@mentor.com> <1470320194-9602-2-git-send-email-Sandeep_Jain@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1470320194-9602-2-git-send-email-Sandeep_Jain@mentor.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: [137.202.0.87] X-ClientProxiedBy: svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1940 Lines: 63 Dear Maintainers, Requesting for your attention for patch review/merge. Thanks & Regards, Sandeep Jain On Thu, Aug 04, 2016 at 07:46:33PM +0530, Sandeep Jain wrote: > From: Vladimir Zapolskiy > > The change controls module users counter, which prevents to get > accidental oops on module unload while it is in use by mtd subsystem: > > % dd if=/dev/mtd0 of=/dev/null & > % rmmod m25p80 > > Removing MTD device #0 (spi32766.0) with use count 1 > Unable to handle kernel paging request at virtual address 7f4fb7f8 > pgd = bd094000 > [7f4fb7f8] *pgd=4cb66811, *pte=00000000, *ppte=00000000 > Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM > > Signed-off-by: Vladimir Zapolskiy > Signed-off-by: Sandeep Jain > --- > drivers/mtd/devices/m25p80.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c > index 9cf7fcd..2eb1530 100644 > --- a/drivers/mtd/devices/m25p80.c > +++ b/drivers/mtd/devices/m25p80.c > @@ -185,6 +185,19 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len, > return ret; > } > > +static void m25p80_put(struct mtd_info *mtd) > +{ > + module_put(THIS_MODULE); > +} > + > +static int m25p80_get(struct mtd_info *mtd) > +{ > + if (!try_module_get(THIS_MODULE)) > + return -ENODEV; > + > + return 0; > +} > + > /* > * board specific setup should have ensured the SPI clock used here > * matches what the READ command supports, at least until this driver > @@ -212,6 +225,8 @@ static int m25p_probe(struct spi_device *spi) > nor->write = m25p80_write; > nor->write_reg = m25p80_write_reg; > nor->read_reg = m25p80_read_reg; > + nor->mtd._put_device = m25p80_put; > + nor->mtd._get_device = m25p80_get; > > nor->dev = &spi->dev; > spi_nor_set_flash_node(nor, spi->dev.of_node); > -- > 1.7.9.5 >