Re: [PATCH v7 10/12] PCI: qcom: Add SM8550 PCIe support

[Johan Hovold]

On Mon, Feb 06, 2023 at 05:11:01PM +0200, Abel Vesa wrote:
> On 23-02-03 10:49:24, Johan Hovold wrote:
> > On Fri, Feb 03, 2023 at 10:18:05AM +0200, Abel Vesa wrote:
> > > Add compatible for both PCIe found on SM8550.
> > > Also add the cnoc_pcie_sf_axi clock needed by the SM8550.
> > 
> > nit: You're now also adding 'noc_aggr'
> > 
> > > Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> > > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> > > Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> > > ---

> > > @@ -182,10 +182,10 @@ struct qcom_pcie_resources_2_3_3 {
> > >  
> > >  /* 6 clocks typically, 7 for sm8250 */
> > >  struct qcom_pcie_resources_2_7_0 {
> > > -	struct clk_bulk_data clks[12];
> > > +	struct clk_bulk_data clks[14];
> > >  	int num_clks;
> > >  	struct regulator_bulk_data supplies[2];
> > > -	struct reset_control *pci_reset;
> > > +	struct reset_control *rst;
> > 
> > Please name this one 'reset' or 'resets' (e.g. to avoid hard to parse
> > things like res->rst below).
> 
> Well, it would then be inconsitent with 2_3_3 and 2_9_0, which both use
> rst.

Yeah, I saw that. Fortunately these resources are completely
independent, but whatever.
 
> > >  };
> > >  
> > >  struct qcom_pcie_resources_2_9_0 {
> > > @@ -1177,9 +1177,9 @@ static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
> > >  	unsigned int idx;
> > >  	int ret;
> > >  
> > > -	res->pci_reset = devm_reset_control_get_exclusive(dev, "pci");
> > > -	if (IS_ERR(res->pci_reset))
> > > -		return PTR_ERR(res->pci_reset);
> > > +	res->rst = devm_reset_control_array_get_exclusive(dev);
> > > +	if (IS_ERR(res->rst))
> > > +		return PTR_ERR(res->rst);
> > 
> > So the reset array implementation apparently both asserts and deasserts
> > the resets in the order specified in DT (i.e. does not deassert in
> > reverse order).
> > 
> > Is that ok also for the new "pci" and "link_down" resets?
> 
> According to the HPG, yes, this is perfectly fine. It specifically says
> to assert the pcie reset and then continues saying to assert the
> link_down reset.

Ok, but that doesn't really say anything about whether it's ok to
*deassert* them in the same order, which was what I asked about.

Johan