Re: [PATCH 1/4] pcie-rcar: poll PHYRDY in rcar_pcie_hw_init()

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On Fri, Apr 06, 2018 at 02:02:52PM +0300, Sergei Shtylyov wrote:
> In  all the R-Car gen1/2/3 manuals, we are instructed to poll PCIEPHYSR
> for PHYRDY=1  at  an early stage of the PCIEC initialization -- while
> the driver only does this on R-Car H1 (polling a PHY specific register).

Is the R-Car H1 specific code still needed with this patch in place?

If so can we consider a helper. rcar_pcie_wait_for_phyrdy() looks
very similar to that R-Car H1 code.

> Add the PHYRDY polling to rcar_pcie_hw_init(). Note that without the
> special PHY driver on the R-Car V3H the PCIEC initialization just freezes
> the kernel --  adding the PHYRDY polling allows the init code to exit
> gracefully on timeout (PHY starts powered down after reset on this SoC).

How widely has this been exercised? I assume it affects Rcar Gen 1, 2 and 3.

> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
> 
> ---
>  drivers/pci/host/pcie-rcar.c |   20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> Index: pci/drivers/pci/host/pcie-rcar.c
> ===================================================================
> --- pci.orig/drivers/pci/host/pcie-rcar.c
> +++ pci/drivers/pci/host/pcie-rcar.c
> @@ -36,6 +36,8 @@
>  #define PCIECDR			0x000020
>  #define PCIEMSR			0x000028
>  #define PCIEINTXR		0x000400
> +#define PCIEPHYSR		0x0007f0
> +#define  PHYRDY			1

Can we start using the BIT() macro in this driver?

>  #define PCIEMSITXR		0x000840
>  
>  /* Transfer control */
> @@ -527,6 +529,20 @@ static void phy_write_reg(struct rcar_pc
>  	phy_wait_for_ack(pcie);
>  }
>  
> +static int rcar_pcie_wait_for_phyrdy(struct rcar_pcie *pcie)
> +{
> +	unsigned int timeout = 10;
> +
> +	while (timeout--) {
> +		if (rcar_pci_read_reg(pcie, PCIEPHYSR) & PHYRDY)
> +			return 0;
> +
> +		msleep(5);
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
>  static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie)
>  {
>  	unsigned int timeout = 10;
> @@ -551,6 +567,10 @@ static int rcar_pcie_hw_init(struct rcar
>  	/* Set mode */
>  	rcar_pci_write_reg(pcie, 1, PCIEMSR);
>  
> +	err = rcar_pcie_wait_for_phyrdy(pcie);
> +	if (err)
> +		return err;
> +
>  	/*
>  	 * Initial header for port config space is type 1, set the device
>  	 * class to match. Hardware takes care of propagating the IDSETR
> 



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