Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 13 Aug 2020 17:41:07 +0200 | Subject | Re: [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable |
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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
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