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

From: Joao Pinto <Joao.Pinto@synopsys.com>
To: Murali Karicheri <m-karicheri2@ti.com>, <jingoohan1@gmail.com>,
	<Joao.Pinto@synopsys.com>, <bhelgaas@google.com>,
	<linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] PCI: designware: fix asynchronous external abort in keystone PCIe h/w
Date: Tue, 10 Jan 2017 10:26:30 +0000	[thread overview]
Message-ID: <d973a128-f038-2cb9-f6d3-d50b9970999c@synopsys.com> (raw)
In-Reply-To: <5873BD56.4040100@ti.com>

Hi,

Às 4:41 PM de 1/9/2017, Murali Karicheri escreveu:
> 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@ti.com>
>> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>  - 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.
> 

In my understanding your proposal will have no impact in platform using ATU, so
for me is fine.

Acked-By: Joao Pinto <jpinto@synopsys.com>

> Thanks
> 