Re: [dpdk-dev] [PATCH v2] igb_uio: add config option to control reset

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

On 11/3/2017 8:51 AM, Ferruh Yigit wrote:
> Adding a compile time configuration option to control device reset done
> during DPDK application exit.
>
> Config option is CONFIG_RTE_EAL_IGB_UIO_RESET and enabled by default,
> so by default reset will happen. Having this reset is safer to be sure
> device left in a proper case.
>
> But for special cases [1] it is possible to disable the config option
> to prevent the device reset.
>
> [1]
> http://dpdk.org/ml/archives/dev/2017-November/080927.html
>
> Fixes: b58eedfc7dd5 ("igb_uio: issue FLR during open and release of device file")
> Cc: stable@dpdk.org
>
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

Realize that we do have a pci_clear_master() in the release() to disable 
the DMA from device until the next open() will enable the DMA again . 
Here is my:

Reviewed-by: Jianfeng Tan <jianfeng.tan@intel.com>

Thanks,
Jianfeng

> ---
> Cc: Jianfeng Tan <jianfeng.tan@intel.com>
> Cc: Jingjing Wu <jingjing.wu@intel.com>
> Cc: Shijith Thotton <shijith.thotton@caviumnetworks.com>
> Cc: Gregory Etelson <gregory@weka.io>
> Cc: Harish Patil <harish.patil@cavium.com>
> Cc: George Prekas <george.prekas@epfl.ch>
> Cc: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
> Cc: Rasesh Mody <rasesh.mody@cavium.com>
>
> v2:
> * fix typo in commit log
> ---
>   config/common_base                        | 1 +
>   config/common_linuxapp                    | 1 +
>   lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 2 ++
>   3 files changed, 4 insertions(+)
>
> diff --git a/config/common_base b/config/common_base
> index 82ee75456..2a9947420 100644
> --- a/config/common_base
> +++ b/config/common_base
> @@ -102,6 +102,7 @@ CONFIG_RTE_LIBEAL_USE_HPET=n
>   CONFIG_RTE_EAL_ALLOW_INV_SOCKET_ID=n
>   CONFIG_RTE_EAL_ALWAYS_PANIC_ON_ERROR=n
>   CONFIG_RTE_EAL_IGB_UIO=n
> +CONFIG_RTE_EAL_IGB_UIO_RESET=n
>   CONFIG_RTE_EAL_VFIO=n
>   CONFIG_RTE_MALLOC_DEBUG=n
>   CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=n
> diff --git a/config/common_linuxapp b/config/common_linuxapp
> index 74c7d64ec..b3a602909 100644
> --- a/config/common_linuxapp
> +++ b/config/common_linuxapp
> @@ -37,6 +37,7 @@ CONFIG_RTE_EXEC_ENV_LINUXAPP=y
>   
>   CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=y
>   CONFIG_RTE_EAL_IGB_UIO=y
> +CONFIG_RTE_EAL_IGB_UIO_RESET=y
>   CONFIG_RTE_EAL_VFIO=y
>   CONFIG_RTE_KNI_KMOD=y
>   CONFIG_RTE_LIBRTE_KNI=y
> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> index fd320d87d..0325722c0 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> @@ -360,7 +360,9 @@ igbuio_pci_release(struct uio_info *info, struct inode *inode)
>   	/* stop the device from further DMA */
>   	pci_clear_master(dev);
>   
> +#ifdef RTE_EAL_IGB_UIO_RESET
>   	pci_reset_function(dev);
> +#endif
>   
>   	return 0;
>   }