Hi Francesco, france...@dolcini.it wrote on Fri, 03 Feb 2023 19:03:27 +0100:
> Il 3 febbraio 2023 16:12:02 CET, Miquel Raynal <miquel.ray...@bootlin.com> ha > scritto: > >Hi Francesco, > > > >france...@dolcini.it wrote on Thu, 2 Feb 2023 12:33:34 +0100: > > > >> On Thu, Jan 26, 2023 at 10:12:04AM +0100, Miquel Raynal wrote: > >> > gre...@linuxfoundation.org wrote on Thu, 26 Jan 2023 10:01:02 +0100: > >> > > >> > > On Wed, Jan 25, 2023 at 10:06:57PM +0100, Francesco Dolcini wrote: > >> > > > Hello Miquel, Greg and all > >> > > > > >> > > > On Tue, Jan 24, 2023 at 04:38:59PM +0100, Greg Kroah-Hartman wrote: > >> > > > > >> > > > > On Tue, Jan 24, 2023 at 11:44:44AM +0100, Francesco Dolcini wrote: > >> > > > > > >> > > > > > From: Francesco Dolcini <francesco.dolc...@toradex.com> > >> > > > > > > >> > > > > > Add a mechanism to handle the case in which partitions are > >> > > > > > present as > >> > > > > > direct child of the nand controller node and #size-cells is set > >> > > > > > to <0>. > >> > > > > > > >> > > > > > This could happen if the nand-controller node in the DTS is > >> > > > > > supposed to > >> > > > > > have #size-cells set to 0, but for some historical reason/bug it > >> > > > > > was set > >> > > > > > to 1 in the past, and the firmware (e.g. U-Boot) is adding the > >> > > > > > partition > >> > > > > > as direct children of the nand-controller defaulting to > >> > > > > > #size-cells > >> > > > > > being to 1. > >> > > > > > > >> > > > > > This prevents a real boot failure on colibri-imx7 that happened > >> > > > > > during v6.1 > >> > > > > > development cycles. > >> > > > > > > >> > > > > > Link: > >> > > > > > https://lore.kernel.org/all/y4dgbtgnwpm6s...@francesco-nb.int.toradex.com/ > >> > > > > > Link: > >> > > > > > https://lore.kernel.org/all/20221202071900.1143950-1-france...@dolcini.it/ > >> > > > > > Signed-off-by: Francesco Dolcini <francesco.dolc...@toradex.com> > >> > > > > > Reviewed-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> > >> > > > > > --- > >> > > > > > I do not expect this patch to be backported to stable, however I > >> > > > > > would expect > >> > > > > > that we do not backport nand-controller dts cleanups neither. > >> > > > > > > >> > > > > > v4: > >> > > > > > fixed wrong English spelling in the comment > >> > > > > > > >> > > > > > v3: > >> > > > > > minor formatting change, removed not needed new-line and space. > >> > > > > > > >> > > > > > v2: > >> > > > > > fixup size-cells only when partitions are direct children of > >> > > > > > the nand-controller > >> > > > > > completely revised commit message, comments and warning print > >> > > > > > use pr_warn instead of pr_warn_once > >> > > > > > added Reviewed-by Greg > >> > > > > > removed cc:stable@ and fixes tag, since the problematic commit > >> > > > > > was reverted > >> > > > > > --- > >> > > > > > drivers/mtd/parsers/ofpart_core.c | 19 +++++++++++++++++++ > >> > > > > > 1 file changed, 19 insertions(+) > >> > > > > > > >> > > > > > diff --git a/drivers/mtd/parsers/ofpart_core.c > >> > > > > > b/drivers/mtd/parsers/ofpart_core.c > >> > > > > > index 192190c42fc8..e7b8e9d0a910 100644 > >> > > > > > --- a/drivers/mtd/parsers/ofpart_core.c > >> > > > > > +++ b/drivers/mtd/parsers/ofpart_core.c > >> > > > > > @@ -122,6 +122,25 @@ static int parse_fixed_partitions(struct > >> > > > > > mtd_info *master, > >> > > > > > > >> > > > > > a_cells = of_n_addr_cells(pp); > >> > > > > > s_cells = of_n_size_cells(pp); > >> > > > > > + if (!dedicated && s_cells == 0) { > >> > > > > > + /* > >> > > > > > + * This is a ugly workaround to not > >> > > > > > create > >> > > > > > + * regression on devices that are still > >> > > > > > creating > >> > > > > > + * partitions as direct children of the > >> > > > > > nand controller. > >> > > > > > + * This can happen in case the nand > >> > > > > > controller node has > >> > > > > > + * #size-cells equal to 0 and the > >> > > > > > firmware (e.g. > >> > > > > > + * U-Boot) just add the partitions > >> > > > > > there assuming > >> > > > > > + * 32-bit addressing. > >> > > > > > + * > >> > > > > > + * If you get this warning your > >> > > > > > firmware and/or DTS > >> > > > > > + * should be really fixed. > >> > > > > > + * > >> > > > > > + * This is working only for devices > >> > > > > > smaller than 4GiB. > >> > > > > > + */ > >> > > > > > + pr_warn("%s: ofpart partition %pOF > >> > > > > > (%pOF) #size-cells is wrongly set to <0>, assuming <1> for > >> > > > > > parsing partitions.\n", > >> > > > > > + master->name, pp, mtd_node); > >> > > > > > > >> > > > > > >> > > > > This is a driver, always use dev_*() calls, not pr_*() calls so > >> > > > > that we > >> > > > > know what is being referred to exactly. > >> > > > > >> > > > Is this reasonable here? Where can I get the struct device? > >> > > > >> > > Walk back up the call chain, there has to be a device somewhere > >> > > controlling this, right? > >> > > > >> > > > In general this file uses only pr_* debug API and messages are about > >> > > > OF > >> > > > nodes/properties, not about a device. > >> > > > >> > > OF nodes and properties are part of a device's properties :) > >> > > >> > Yes but the warning comes from a wrong DT description, hence it felt > >> > better suited to warn against the node name which is easily identifiable > >> > in a text file and must be fixed rather than the device which is a pure > >> > software component. > >> > > >> > Anyway, Francesco, please show us the resultant line and if it feels > >> > meaningful enough we'll take the dev_warn approach. > >> > >> So, I tried, but I guess I failed. > >> > >> Both > >> > >> dev_warn(&mtd_get_master(master)->dev, ...); > >> > >> and > >> > >> dev_warn(&master->dev, ...); > >> > >> are NULL. > > > >mtd->dev (in raw NAND) is populated by the controller drivers, so the > >master mtd device is pointing to the bus "struct device" in its > >dev.parent field. This happens at the end of the probe of the > >controller, after setting the dev entry, so we expect the name of the > >controller to appear. > > > >> (null): gpmi-nand: ofpart partition > >> /soc/nand-controller@33002000/partition@0 (/soc/nand-controller@33002000) > >> #size-cells is wrongly set to <0>, assuming <1> for parsing partitions. > > > >Second field looks right, first field does not (bus or class id?) I > >have no idea why it has not been populated at this point (end of the > >controller probe). But it's not a big deal, at least we have the device > >name, so it's ok for me. > > If I understand correctly you are fine with the current patch v4 that just > print (on colibri-imx7) Well, yes I was fine with it, but no that's not what I meant. AFAIS, using dev_warn() starts with "(null): gpmi-nand:" while pr_warn started with "gpmi-nand:", so for me the main and relevant information is present, that's all what I care about. Greg cared about the API used so I believe he would prefer us to use dev_warn(). It is unusual to apply a patch on which someone active in the community answered negatively as long as his concerns can be addressed, so I would like Greg to either state that he is fine with the pr_warn or you to send a v5 using dev_warn() and him to send his R-by back. If this happens early next week I'll take the patch for my next PR. > gpmi-nand: ofpart partition /soc/nand-controller@33002000/partition@0 > (/soc/nand-controller@33002000) #size-cells is wrongly set to <0>, assuming > <1> for parsing partitions. > > Correct? Do you want a v5 with the reviewed-by greg removed or you remove it > yourself? > > Francesco > Thanks, Miquèl
