On 2/8/24 12:52, David Ventura wrote:
> During IP auto configuration, some drivers apparently need to wait a
> certain length of time to settle; as this is not true for all drivers,
> make this length of time configurable.
>
> Signed-off-by: David Ventura <david@xxxxxxxxxx>
> ---
> .../admin-guide/kernel-parameters.txt | 4 ++++
> Documentation/admin-guide/nfs/nfsroot.rst | 3 +++
> net/ipv4/ipconfig.c | 23 ++++++++++++++++---
> 3 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index b47940577c10..b07a035642fa 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2291,6 +2291,10 @@
>
> ip= [IP_PNP]
> See Documentation/admin-guide/nfs/nfsroot.rst.
> + ip.dev_wait_ms=
> + [IP_PNP]
> + See Documentation/admin-guide/nfs/nfsroot.rst.
> +
>
> ipcmni_extend [KNL,EARLY] Extend the maximum number of unique System V
> IPC identifiers from 32,768 to 16,777,216.
> diff --git a/Documentation/admin-guide/nfs/nfsroot.rst b/Documentation/admin-guide/nfs/nfsroot.rst
> index 135218f33394..f26f7a342af6 100644
> --- a/Documentation/admin-guide/nfs/nfsroot.rst
> +++ b/Documentation/admin-guide/nfs/nfsroot.rst
> @@ -223,6 +223,9 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:<dns
> /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real
> root filesystem if it is on NFS).
>
> +ip.dev_wait_ms=<value>
> + Set the number of milliseconds to delay after opening the network device
> + which will be autoconfigured. Defaults to 10 milliseconds.
>
> nfsrootdebug
> This parameter enables debugging messages to appear in the kernel
> diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
> index c56b6fe6f0d7..cbf35163b973 100644
> --- a/net/ipv4/ipconfig.c
> +++ b/net/ipv4/ipconfig.c
> @@ -82,8 +82,6 @@
> #define IPCONFIG_DYNAMIC
> #endif
>
> -/* Define the friendly delay before and after opening net devices */
> -#define CONF_POST_OPEN 10 /* After opening: 10 msecs */
>
> /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
> #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
> @@ -101,6 +99,7 @@
>
> /* Wait for carrier timeout default in seconds */
> static unsigned int carrier_timeout = 120;
> +static unsigned int dev_wait_ms = 10;
>
> /*
> * Public IP configuration
> @@ -1516,7 +1515,8 @@ static int __init ip_auto_config(void)
> return err;
>
> /* Give drivers a chance to settle */
> - msleep(CONF_POST_OPEN);
> + if(dev_wait_ms > 0)
> + msleep(dev_wait_ms);
What's the point to wait more than CONF_POST_OPEN with the change?
>
> /*
> * If the config information is insufficient (e.g., our IP address or
> @@ -1849,3 +1849,20 @@ static int __init set_carrier_timeout(char *str)
> return 1;
> }
> __setup("carrier_timeout=", set_carrier_timeout);
> +
> +
> +static int __init set_dev_wait_ms(char *str)
> +{
> + ssize_t ret;
> +
> + if (!str)
> + return 0;
> +
> + ret = kstrtouint(str, 0, &dev_wait_ms);
> + if (ret)
> + return 0;
> +
> + return 1;
> +}
> +
> +__setup("ip.dev_wait_ms=", set_dev_wait_ms);
