From: Arnd Bergmann <arnd@arndb.de> To: Daniel Gutson <daniel@eclypsium.com> Cc: Tudor Ambarus <tudor.ambarus@microchip.com>, Miquel Raynal <miquel.raynal@bootlin.com>, Richard Weinberger <richard@nod.at>, Vignesh Raghavendra <vigneshr@ti.com>, Mika Westerberg <mika.westerberg@linux.intel.com>, Boris Brezillon <bbrezillon@kernel.org>, linux-mtd <linux-mtd@lists.infradead.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Alex Bazhaniuk <alex@eclypsium.com>, Richard Hughes <hughsient@gmail.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org> Subject: Re: [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable Date: Thu, 13 Aug 2020 17:41:07 +0200 [thread overview] Message-ID: <CAK8P3a13N_wNORz_3cYHTN8t29pPrY+dJ+g+1Ga_MmG1TmrUQw@mail.gmail.com> (raw) In-Reply-To: <CAFmMkTFzmC=aY0gR6urLu-8Oq8aeHBUWi-TodG8XhXKCcC057A@mail.gmail.com> On Tue, Aug 4, 2020 at 11:26 PM Daniel Gutson <daniel@eclypsium.com> wrote: > On Tue, Aug 4, 2020 at 5:46 PM Arnd Bergmann <arnd@arndb.de> wrote: > > > But wait, Mika, the author of the file, asked earlier not to remove > > > the module parameter of intel-spi, and just remove the unconditional > > > attempt to turn the chip writable in intle-spi-pci. > > > > Yes, and I think that is fine (aside from the inconsistency with bay trail > > that you have not commented on), > > There are two inconsistencies before any of my patches: > 1) in intel-spi.c: uses the module parameter only for bay trail. > 2) intel-spi.c uses a module parameter whereas intel-spi-pci doesn't Neither of these matches what I see in the source code. Please check again. Once more: intel-spi.c has a module parameter that controls writing to the device regardless of the back-end (platform or pci), purely in software. The hardware write-protect setting where available works in addition that and prevents writing even if the module parameter is set to writeable. > > but that only touches the hardware > > write-protection, which doesn't really have any effect unless user > > space also configures the driver module to allow writing to the > > mtd device. > > > > > So I'm not touching intel-pci, just removing that code from > > > intel-spi-pci without adding a new module parameter. > > > > > > Are you aligned on this? > > > > One of us is still very confused about what the driver does. > > You seem to have gone back to saying that without the > > change a user could just write to the device even without > > passing the module parameter to intel-spi.ko? > > What I'm trying to say is that, if the BIOS is unlocked > (no driver involvement here), the intel-spi-pci turns the > chip writable even without changing the module parameter of intel-spi. > This is because the attempt to turn the chip writable occurs in > the probing of intel-spi-pci, that is, earlier than the intel-spi > initialization. My question was why you even care whether the hardware bit is set to writeable if the driver disallows writing. I think the answer is that you misread the driver. Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de> To: Daniel Gutson <daniel@eclypsium.com> Cc: Richard Hughes <hughsient@gmail.com>, Vignesh Raghavendra <vigneshr@ti.com>, Boris Brezillon <bbrezillon@kernel.org>, Richard Weinberger <richard@nod.at>, Tudor Ambarus <tudor.ambarus@microchip.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-mtd <linux-mtd@lists.infradead.org>, Miquel Raynal <miquel.raynal@bootlin.com>, Alex Bazhaniuk <alex@eclypsium.com>, Mika Westerberg <mika.westerberg@linux.intel.com> Subject: Re: [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable Date: Thu, 13 Aug 2020 17:41:07 +0200 [thread overview] Message-ID: <CAK8P3a13N_wNORz_3cYHTN8t29pPrY+dJ+g+1Ga_MmG1TmrUQw@mail.gmail.com> (raw) In-Reply-To: <CAFmMkTFzmC=aY0gR6urLu-8Oq8aeHBUWi-TodG8XhXKCcC057A@mail.gmail.com> On Tue, Aug 4, 2020 at 11:26 PM Daniel Gutson <daniel@eclypsium.com> wrote: > On Tue, Aug 4, 2020 at 5:46 PM Arnd Bergmann <arnd@arndb.de> wrote: > > > But wait, Mika, the author of the file, asked earlier not to remove > > > the module parameter of intel-spi, and just remove the unconditional > > > attempt to turn the chip writable in intle-spi-pci. > > > > Yes, and I think that is fine (aside from the inconsistency with bay trail > > that you have not commented on), > > There are two inconsistencies before any of my patches: > 1) in intel-spi.c: uses the module parameter only for bay trail. > 2) intel-spi.c uses a module parameter whereas intel-spi-pci doesn't Neither of these matches what I see in the source code. Please check again. Once more: intel-spi.c has a module parameter that controls writing to the device regardless of the back-end (platform or pci), purely in software. The hardware write-protect setting where available works in addition that and prevents writing even if the module parameter is set to writeable. > > but that only touches the hardware > > write-protection, which doesn't really have any effect unless user > > space also configures the driver module to allow writing to the > > mtd device. > > > > > So I'm not touching intel-pci, just removing that code from > > > intel-spi-pci without adding a new module parameter. > > > > > > Are you aligned on this? > > > > One of us is still very confused about what the driver does. > > You seem to have gone back to saying that without the > > change a user could just write to the device even without > > passing the module parameter to intel-spi.ko? > > What I'm trying to say is that, if the BIOS is unlocked > (no driver involvement here), the intel-spi-pci turns the > chip writable even without changing the module parameter of intel-spi. > This is because the attempt to turn the chip writable occurs in > the probing of intel-spi-pci, that is, earlier than the intel-spi > initialization. My question was why you even care whether the hardware bit is set to writeable if the driver disallows writing. I think the answer is that you misread the driver. Arnd ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2020-08-13 15:41 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-08-04 13:58 [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable Daniel Gutson 2020-08-04 13:58 ` Daniel Gutson 2020-08-04 14:08 ` Mika Westerberg 2020-08-04 14:08 ` Mika Westerberg 2020-08-04 15:21 ` Arnd Bergmann 2020-08-04 15:21 ` Arnd Bergmann [not found] ` <CAFmMkTHEm8k+5GZkVJbDZMEhMwpsqVKRb-hGskSpBstdLRuFyA@mail.gmail.com> 2020-08-04 19:06 ` Arnd Bergmann 2020-08-04 19:06 ` Arnd Bergmann 2020-08-04 19:57 ` Daniel Gutson 2020-08-04 19:57 ` Daniel Gutson 2020-08-04 20:46 ` Arnd Bergmann 2020-08-04 20:46 ` Arnd Bergmann 2020-08-04 21:26 ` Daniel Gutson 2020-08-04 21:26 ` Daniel Gutson 2020-08-12 15:41 ` Daniel Gutson 2020-08-12 15:41 ` Daniel Gutson 2020-08-13 9:01 ` Greg Kroah-Hartman 2020-08-13 9:01 ` Greg Kroah-Hartman [not found] ` <CAFmMkTFgjW+9gNfx=2SU7B0foww=SLiiyVi+P-hZpEFDbMTf2Q@mail.gmail.com> 2020-08-13 11:47 ` Greg Kroah-Hartman 2020-08-13 11:47 ` Greg Kroah-Hartman 2020-08-13 15:41 ` Arnd Bergmann [this message] 2020-08-13 15:41 ` Arnd Bergmann 2020-08-13 21:40 ` Daniel Gutson 2020-08-13 21:40 ` Daniel Gutson 2020-08-16 8:41 ` Arnd Bergmann 2020-08-16 8:41 ` Arnd Bergmann 2020-08-18 15:55 ` Daniel Gutson 2020-08-18 15:55 ` Daniel Gutson 2020-08-19 6:57 ` Mika Westerberg 2020-08-19 6:57 ` Mika Westerberg 2020-08-19 8:38 ` Arnd Bergmann 2020-08-19 8:38 ` Arnd Bergmann 2020-08-19 9:11 ` Mika Westerberg 2020-08-19 9:11 ` Mika Westerberg 2020-08-22 16:06 ` Arnd Bergmann 2020-08-22 16:06 ` Arnd Bergmann 2020-08-24 8:22 ` Mika Westerberg 2020-08-24 8:22 ` Mika Westerberg 2020-08-24 9:08 ` Arnd Bergmann 2020-08-24 9:08 ` Arnd Bergmann 2020-08-24 9:15 ` Mika Westerberg 2020-08-24 9:15 ` Mika Westerberg 2020-08-24 9:31 ` Arnd Bergmann 2020-08-24 9:31 ` Arnd Bergmann 2020-08-24 9:44 ` Mika Westerberg 2020-08-24 9:44 ` Mika Westerberg 2020-08-24 16:00 ` Daniel Gutson 2020-08-24 16:00 ` Daniel Gutson 2020-08-19 9:19 ` David Laight 2020-08-19 9:19 ` David Laight
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