Re: [PATCH] PCI: designware: fix asynchronous external abort in keystone PCIe h/w

[Murali Karicheri]

On 01/04/2017 02:32 PM, Murali Karicheri wrote:
> Recent fixes for iATU unroll support introduced a bug that causes
> asynchronous external abort in Keystone PCIe h/w which doesn't have
> ATU port and the corresponding register. So the check should be moved
> below where dw_pcie_prog_outbound_atu() is called to avoid that
> being called on keystine PCIe h/w.
> 
> Here is the backtrace
> 
> [    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
> [    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
> [    0.785548] pgd = c0003000
> [    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
> [    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
> [    0.799197] Modules linked in:
> [    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
> [    0.810130] Hardware name: Keystone
> [    0.813717] task: eb878000 task.stack: eb866000
> [    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
> [    0.823083] LR is at ks_pcie_host_init+0x10/0x170
> 
> Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
> Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
> Tested-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
>  - Applies to pci/master
>  - Bug was introduced in v4.9
>  - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card
> 
>  drivers/pci/host/pcie-designware.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index bed1999..af8f6e9 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  {
>  	u32 val;
>  
> -	/* get iATU unroll support */
> -	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> -	dev_dbg(pp->dev, "iATU unroll: %s\n",
> -		pp->iatu_unroll_enabled ? "enabled" : "disabled");
> -
>  	/* set the number of lanes */
>  	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
>  	val &= ~PORT_LINK_MODE_MASK;
> @@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  	 * we should not program the ATU here.
>  	 */
>  	if (!pp->ops->rd_other_conf) {
> +		/* get iATU unroll support */
> +		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> +		dev_dbg(pp->dev, "iATU unroll: %s\n",
> +			pp->iatu_unroll_enabled ? "enabled" : "disabled");
> +
>  		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
>  					  PCIE_ATU_TYPE_MEM, pp->mem_base,
>  					  pp->mem_bus_addr, pp->mem_size);
> 
Bjorn,

A Gentle ping to merge this important fix to v4.10-rc kernel for Keystone PCI as
it is broken since v4.9.

Thanks

-- 
Murali Karicheri
Linux Kernel, Keystone