On Fri, Feb 03, 2023 at 07:37:03PM +0100, Francesco Dolcini wrote: > > > Il 3 febbraio 2023 19:16:23 CET, Miquel Raynal <miquel.ray...@bootlin.com> ha > scritto: > >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. > > Perfect, I understand and agree. > > I was somehow puzzled because changing to dev_warn() on this specific warning > message while the whole file already uses pr_warn() just to get a "(null):" > prefix in the logs seems a little pointless to me.
Yeah, if the whole rest of the file is this way, a pr_warn() is fine for now to solve the real problem. You can resolve the use of dev_warn() later in a follow-on patch once the (null) issues get resolved (as that's obviously not ok...) thanks, greg k-h
