Hi Greg, france...@dolcini.it wrote on Wed, 25 Jan 2023 22:06:57 +0100:
> 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? > > In general this file uses only pr_* debug API and messages are about OF > nodes/properties, not about a device. I'm also skeptical here, this is not a device driver, it's a generic parser and it seems more appropriate to warn about an of node rather than a struct device. MTD devices inherit from struct device (mtd->dev) which I guess might be used here. The bus infrastructure device (mtd->device->parents) is less appropriate as it sometimes points at the controller (raw NAND) and sometimes at the spi device (SPI-NAND, SPI NOR). pr_warn is fine here IMHO, but if Greg insist, switch it to dev_warn, I don't mind. Maybe it is worth testing that dev_warn still displays an easy-to-understand message in that case. > > I take back my "reviewed-by" line above, please fix this up to not need > > pr_warn, but to use dev_warn() instead. > > Francesco Thanks, Miquèl