Re: [PATCH] PCI: Mediatek: Use resource_size function on resource object

[Bjorn Helgaas]

On Wed, Jan 30, 2019 at 12:33:47PM +0000, Lorenzo Pieralisi wrote:
> On Wed, Jan 02, 2019 at 02:03:53PM +0800, honghui.zhang@xxxxxxxxxxxx wrote:
> > From: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
> > 
> > drivers/pci/pcie-mediatek.c:720:13-16: WARNING: Suspicious code. resource_size is maybe missing with mem
> > 
> > Generated by: scripts/coccinelle/api/resource_size.cocci
> > 
> > Signed-off-by: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
> > ---
> >  drivers/pci/controller/pcie-mediatek.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
> > index e307166..0168376 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 +705,7 @@ 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)));
> 
> checkpatch warns on this line, please make sure patches pass it before
> posting them.

I didn't actually run checkpatch myself, so I don't know why it
complained.

The patch you merged moves "mem_size = resource_size(mem)" higher up,
away from the previous location and its use, which makes it a little
harder to read.

Bjorn