From: Francesco Dolcini francesco.dolcini@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/Y4dgBTGNWpM6SQXI@francesco-nb.int.toradex.com/ Link: https://lore.kernel.org/all/20221202071900.1143950-1-francesco@dolcini.it/ Signed-off-by: Francesco Dolcini francesco.dolcini@toradex.com Reviewed-by: Greg Kroah-Hartman gregkh@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.

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..5077000a00e6 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 hugly workaround to not create + * regression on devices that are still creating + * partitions as direct child 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); + s_cells = 1; + } if (len / 4 != a_cells + s_cells) { pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n", master->name, pp,