On Thu, Mar 28, 2024 at 03:44:15PM +0100, Rafał Miłecki wrote: > On 2024-03-28 15:19, Christian Marangi wrote: > > On Wed, Mar 27, 2024 at 11:15:02PM +0100, Rafał Miłecki wrote: > > > On 22.03.2024 05:09, Christian Marangi wrote: > > > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c > > > > index 5887feb347a4..0de87bc63840 100644 > > > > --- a/drivers/mtd/mtdcore.c > > > > +++ b/drivers/mtd/mtdcore.c > > > > @@ -900,7 +900,7 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd, > > > > config.name = compatible; > > > > config.id = NVMEM_DEVID_AUTO; > > > > config.owner = THIS_MODULE; > > > > - config.add_legacy_fixed_of_cells = true; > > > > + config.add_legacy_fixed_of_cells = !mtd_type_is_nand(mtd); > > > > config.type = NVMEM_TYPE_OTP; > > > > config.root_only = true; > > > > config.ignore_wp = true; > > > > > > I think there may be even more unwanted behaviour here. If > > > mtd_otp_nvmem_register() fails to find node with "user-otp" / > > > "factory-otp" compatible then it sets "config.of_node" to NULL but > > > that > > > means NVMEM core still looks for NVMEM cells in device's "of_node". > > > > > > I believe we should not look for OTP NVMEM cells out of the > > > "user-otp" / > > > "factory-otp" compatible nodes. > > > > > > So maybe what we need in the first place is just: > > > config.add_legacy_fixed_of_cells = !!np; > > > ? > > > > > > Any extra limitation of .add_legacy_fixed_of_cells should probably be > > > used only if we want to prevent new users of the legacy syntax. The > > > problem is that mtd.yaml binding allowed "user-otp" and "factory-otp" > > > with old syntax cells. It means every MTD device was allowed to have > > > them. > > > > > > No in-kernel DTS even used "user-otp" or "factory-otp" with NVMEM > > > legacy > > > cells but I'm not sure about downstream DTS files. Ideally we would do > > > config.add_legacy_fixed_of_cells = false; > > > but that could break compatibility with some downstream DTS files. > > > > Yes the main problem is prevent regression in downstream. I feel for the > > nand usage, this is 100% of the times broken. For SPI and other corner > > case MTD devices it's not? > > > > Anyway did you by chance have a suggestion for a better fixes tag? > > My personal idea for that would be to put two Fixes with two commits and > describe in commit body that one just exposed existing bug. > > You may check my OpenWrt quick patch for an idea how I'd handle that: > https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/generic/pending-6.6/440-mtd-don-t-look-for-OTP-legacy-NVMEM-cells-if-proper-.patch;h=d9d15a4048c144d8565c8ea38e15a79f7f4a5fe1;hb=dd78a59cd7b029560b33cb3ac0e1aa8b747bd807 > My concern is that using !!np might pose some regression problem. Also I feel adding the macronix commit in fixes tag might be confusing? Think I will just use the nand check just to be extra safe and add a kernel dependency for when the add_legacy_fixed_of_cells was introduced since before that a different patch is needed. What do you think? -- Ansuel
