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From: Sascha Hauer <s.hauer@pengutronix.de>
To: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: barebox@lists.infradead.org, Lucas Stach <lst@pengutronix.de>
Subject: Re: [PATCH 6/6] i.MX6: pci: Avoid aborts when asserting PCIe reset
Date: Mon, 4 Jan 2016 10:30:37 +0100	[thread overview]
Message-ID: <20160104093037.GG13058@pengutronix.de> (raw)
In-Reply-To: <1451627918-31967-6-git-send-email-andrew.smirnov@gmail.com>


The PCI patches look good to me. I'll give Lucas the change to look over
them.

Sascha

On Thu, Dec 31, 2015 at 09:58:38PM -0800, Andrey Smirnov wrote:
> When booting Barebox in the HW environment where PCIe core has been
> used but not properly shut down, writing to PCIE_PL_PFLR in
> imx6_pcie_assert_core_reset would cause data abort exception.
> 
> The problem can be easily reproduced on a i.MX6 based board with PCIe
> slot populated with some device by doing:
> 
> > bootm -f -e 0x1050 <your board's>.img
> 
> Ignoring this exception seem to allow PCIe core to successfully
> initialize and enumerate devices properly. This is also how Linux
> Kernel version of the driver handles this situation -- it installs
> dummy no-op abort handler at the beginning of device's probing.
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  drivers/pci/pci-imx6.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/pci-imx6.c b/drivers/pci/pci-imx6.c
> index 713007b..3a3edd8 100644
> --- a/drivers/pci/pci-imx6.c
> +++ b/drivers/pci/pci-imx6.c
> @@ -13,6 +13,7 @@
> 
>  #include <common.h>
>  #include <clock.h>
> +#include <abort.h>
>  #include <malloc.h>
>  #include <io.h>
>  #include <init.h>
> @@ -237,7 +238,10 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
>  		val = readl(pp->dbi_base + PCIE_PL_PFLR);
>  		val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
>  		val |= PCIE_PL_PFLR_FORCE_LINK;
> +
> +		data_abort_mask();
>  		writel(val, pp->dbi_base + PCIE_PL_PFLR);
> +		data_abort_unmask();
> 
>  		gpr12 &= ~IMX6Q_GPR12_PCIE_CTL_2;
>  		writel(gpr12, imx6_pcie->iomuxc_gpr + IOMUXC_GPR12);
> --
> 2.5.0
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 

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  reply	other threads:[~2016-01-04  9:31 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-01  5:58 [PATCH 1/6] ARM: asm: Add convenience fucntions to access VBAR Andrey Smirnov
2016-01-01  5:58 ` [PATCH 2/6] ARM: mmu: Add VBAR setup Andrey Smirnov
2016-01-04  9:04   ` Sascha Hauer
2016-01-01  5:58 ` [PATCH 3/6] ARM: Fix exception table setup in MMU-less mode Andrey Smirnov
2016-01-04  9:27   ` Sascha Hauer
2016-01-04 17:01     ` Andrey Smirnov
2016-01-05  7:40       ` Sascha Hauer
2016-01-01  5:58 ` [PATCH 4/6] i.MX6: pci: Replace magic number with a named constant Andrey Smirnov
2016-01-07  9:04   ` Lucas Stach
2016-01-08  7:53     ` Sascha Hauer
2016-01-01  5:58 ` [PATCH 5/6] i.MX6: pci: Reconcile imx6_pcie_start_link with the kernel code Andrey Smirnov
2016-01-07  9:08   ` Lucas Stach
2016-01-01  5:58 ` [PATCH 6/6] i.MX6: pci: Avoid aborts when asserting PCIe reset Andrey Smirnov
2016-01-04  9:30   ` Sascha Hauer [this message]
2016-01-07  9:13   ` Lucas Stach

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