Re: [PATCH v5 1/4] PCI: j721e: Add per platform maximum lane settings

[Matt Ranostay <mranostay@ti.com>]

On Thu, Nov 10, 2022 at 04:46:21PM +0100, Lorenzo Pieralisi wrote:
> On Wed, Nov 09, 2022 at 12:25:53AM -0800, Matt Ranostay wrote:
> > Various platforms have different maximum amount of lanes that
> > can be selected. Add max_lanes to struct j721e_pcie to allow
> > for error checking on num-lanes selection from device tree.
> 
> https://lore.kernel.org/linux-pci/CAL_JsqJ5cOLXhD-73esmhVwMEWGT+w3SJC14Z0jY4tQJQRA7iw@mail.gmail.com
> 
> Why have you reposted this patch ?
> 

Max lanes is still needed to calculate the bitmask (i.e. 2x needing one-bit mask, and 4x needing 2-bit mask), but
noticed that I should have change th commit message to be more clear, and drop the part of it being for device-tree
validation..

'PCI: j721e: Add warnings on num-lanes misconfiguration' could be dropped in the series if validation
should be done in the YAML schema checking.

- Matt

> Lorenzo
> 
> > Signed-off-by: Matt Ranostay <mranostay@ti.com>
> > Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
> > ---
> >  drivers/pci/controller/cadence/pci-j721e.c | 11 ++++++++---
> >  1 file changed, 8 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> > index a82f845cc4b5..875224d34958 100644
> > --- a/drivers/pci/controller/cadence/pci-j721e.c
> > +++ b/drivers/pci/controller/cadence/pci-j721e.c
> > @@ -48,8 +48,6 @@ enum link_status {
> >  
> >  #define GENERATION_SEL_MASK		GENMASK(1, 0)
> >  
> > -#define MAX_LANES			2
> > -
> >  struct j721e_pcie {
> >  	struct cdns_pcie	*cdns_pcie;
> >  	struct clk		*refclk;
> > @@ -72,6 +70,7 @@ struct j721e_pcie_data {
> >  	unsigned int		quirk_disable_flr:1;
> >  	u32			linkdown_irq_regfield;
> >  	unsigned int		byte_access_allowed:1;
> > +	unsigned int		max_lanes;
> >  };
> >  
> >  static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
> > @@ -291,11 +290,13 @@ static const struct j721e_pcie_data j721e_pcie_rc_data = {
> >  	.quirk_retrain_flag = true,
> >  	.byte_access_allowed = false,
> >  	.linkdown_irq_regfield = LINK_DOWN,
> > +	.max_lanes = 2,
> >  };
> >  
> >  static const struct j721e_pcie_data j721e_pcie_ep_data = {
> >  	.mode = PCI_MODE_EP,
> >  	.linkdown_irq_regfield = LINK_DOWN,
> > +	.max_lanes = 2,
> >  };
> >  
> >  static const struct j721e_pcie_data j7200_pcie_rc_data = {
> > @@ -303,23 +304,27 @@ static const struct j721e_pcie_data j7200_pcie_rc_data = {
> >  	.quirk_detect_quiet_flag = true,
> >  	.linkdown_irq_regfield = J7200_LINK_DOWN,
> >  	.byte_access_allowed = true,
> > +	.max_lanes = 2,
> >  };
> >  
> >  static const struct j721e_pcie_data j7200_pcie_ep_data = {
> >  	.mode = PCI_MODE_EP,
> >  	.quirk_detect_quiet_flag = true,
> >  	.quirk_disable_flr = true,
> > +	.max_lanes = 2,
> >  };
> >  
> >  static const struct j721e_pcie_data am64_pcie_rc_data = {
> >  	.mode = PCI_MODE_RC,
> >  	.linkdown_irq_regfield = J7200_LINK_DOWN,
> >  	.byte_access_allowed = true,
> > +	.max_lanes = 1,
> >  };
> >  
> >  static const struct j721e_pcie_data am64_pcie_ep_data = {
> >  	.mode = PCI_MODE_EP,
> >  	.linkdown_irq_regfield = J7200_LINK_DOWN,
> > +	.max_lanes = 1,
> >  };
> >  
> >  static const struct of_device_id of_j721e_pcie_match[] = {
> > @@ -433,7 +438,7 @@ static int j721e_pcie_probe(struct platform_device *pdev)
> >  	pcie->user_cfg_base = base;
> >  
> >  	ret = of_property_read_u32(node, "num-lanes", &num_lanes);
> > -	if (ret || num_lanes > MAX_LANES)
> > +	if (ret || num_lanes > data->max_lanes)
> >  		num_lanes = 1;
> >  	pcie->num_lanes = num_lanes;
> >  
> > -- 
> > 2.38.GIT
> >