Commit cc216e4b44ce ("net: sunhme: Switch SBUS to devres") changed explicit sized of_ioremap with BMAC_REG_SIZEs to devm_platform_ioremap_resource mapping all the resource. However, this does not work on my Sun Ultra 2 with SBUS HMEs: hme f0072f38: error -EBUSY: can't request region for resource [mem 0x1ffe8c07000-0x1ffe8c0701f] hme f0072f38: Cannot map TCVR registers. hme f0072f38: probe with driver hme failed with error -16 hme f007ab44: error -EBUSY: can't request region for resource [mem 0x1ff28c07000-0x1ff28c0701f] hme f007ab44: Cannot map TCVR registers. hme f007ab44: probe with driver hme failed with error -16 Turns out the open-firmware resources overlap, at least on this machines and PROM version: hexdump /proc/device-tree/sbus@1f,0/SUNW,hme@2,8c00000/reg: 00 00 00 02 08 c0 00 00 00 00 01 08 00 00 00 02 08 c0 20 00 00 00 20 00 00 00 00 02 08 c0 40 00 00 00 20 00 00 00 00 02 08 c0 60 00 00 00 20 00 00 00 00 02 08 c0 70 00 00 00 00 20 And the driver previously explicitly mapped way smaller mmio regions: /proc/iomem: 1ff28c00000-1ff28c00107 : HME Global Regs 1ff28c02000-1ff28c02033 : HME TX Regs 1ff28c04000-1ff28c0401f : HME RX Regs 1ff28c06000-1ff28c0635f : HME BIGMAC Regs 1ff28c07000-1ff28c0701f : HME Tranceiver Regs Quirk this specific issue by truncating the previous resource to not overlap into the TCVR registers. Fixes: cc216e4b44ce ("net: sunhme: Switch SBUS to devres") Signed-off-by: René Rebe --- Tested on Sun Ultra 2 running T2/Linux. Alternatively we could explicitly size all regions, or check overlap in startup code (I also already have a patch for that, too). --- --- linux-6.18/drivers/net/ethernet/sun/sunhme.c.vanilla 2026-02-05 11:50:33.288906134 +0100 +++ linux-6.18/drivers/net/ethernet/sun/sunhme.c 2026-02-05 11:55:22.541384377 +0100 @@ -2551,6 +2551,9 @@ goto err_out_clear_quattro; } + /* BIGMAC may have bogus sizes */ + if ((op->resource[3].end - op->resource[3].start) >= BMAC_REG_SIZE) + op->resource[3].end = op->resource[3].start + BMAC_REG_SIZE - 1; hp->bigmacregs = devm_platform_ioremap_resource(op, 3); if (IS_ERR(hp->bigmacregs)) { dev_err(&op->dev, "Cannot map BIGMAC registers.\n"); -- René Rebe, ExactCODE GmbH, Berlin, Germany https://exactco.de • https://t2linux.com • https://patreon.com/renerebe