On Thu, Jan 31, 2019 at 04:01:52PM +0800, honghui.zhang@xxxxxxxxxxxx wrote: > From: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx> > > scripts/coccinelle/api/resource_size.cocci complain about the > following warning: > > pcie-mediatek.c:720:13-16: WARNING: Suspicious code. resource_size is maybe missing with mem > > Use resource_size(mem) instead of mem->end - mem->start to eliminate the > complain. Since the MMIO window size for both MT2712 and MT7622 are all > 0x1000_0000, this change also fix the AHB2PCIe window size smaller than > HW MMIO window size issue by change the values of fls(size) from > fls(0xfff_ffff) to fls(0x1000_0000). Good, I'm glad this actually fixes a bug. The warning was actually useful! Since that's the case, the *bug* is the important thing (not the warning), and the subject line should be about the bug fix. The fact that it also happens to remove a warning is really just incidental. You say "the AHB2PCIe window size smaller than HW MMIO window size issue" as though it should be familiar to us. But it's not :) So the changelog needs to start by explaining what the AHB2PCIe window size issue is, mention what user-visible problem that causes, then explain how you're fixing it by using resource_size(). Then you can mention that this also incidentally removes a coccinelle warning. Bjorn > Signed-off-by: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx> > --- > drivers/pci/controller/pcie-mediatek.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c > index 55e471c..01126b8 100644 > --- a/drivers/pci/controller/pcie-mediatek.c > +++ b/drivers/pci/controller/pcie-mediatek.c > @@ -654,7 +654,6 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port) > struct resource *mem = &pcie->mem; > const struct mtk_pcie_soc *soc = port->pcie->soc; > u32 val; > - size_t size; > int err; > > /* MT7622 platforms need to enable LTSSM and ASPM from PCIe subsys */ > @@ -706,8 +705,8 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port) > mtk_pcie_enable_msi(port); > > /* Set AHB to PCIe translation windows */ > - size = mem->end - mem->start; > - val = lower_32_bits(mem->start) | AHB2PCIE_SIZE(fls(size)); > + val = lower_32_bits(mem->start) > + | AHB2PCIE_SIZE(fls(resource_size(mem))); Nit: I think it's more typical to put the "|" on the first line. > writel(val, port->base + PCIE_AHB_TRANS_BASE0_L); > > val = upper_32_bits(mem->start); > -- > 2.6.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
