From: Andrew Lunn <andrew@lunn•ch>
To: Bartosz Golaszewski <brgl@bgdev•pl>
Cc: Rob Herring <robh@kernel•org>,
Grygorii Strashko <grygorii.strashko@ti•com>,
David Lechner <david@lechnology•com>,
Ivan Khoronzhuk <ivan.khoronzhuk@linaro•org>,
Kevin Hilman <khilman@kernel•org>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
Sekhar Nori <nsekhar@ti•com>,
Russell King <linux@armlinux•org.uk>,
linux-kernel@vger•kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre•com>,
Lukas Wunner <lukas@wunner•de>,
Srinivas Kandagatla <srinivas.kandagatla@linaro•org>,
linux-arm-kernel@lists•infradead.org, netdev@vger•kernel.org,
Florian Fainelli <f.fainelli@gmail•com>,
linux-omap@vger•kernel.org,
"David S . Miller" <davem@davemloft•net>,
Dan Carpenter <dan.carpenter@oracle•com>
Subject: Re: [PATCH 4/5] net: add support for nvmem to eth_platform_get_mac_address()
Date: Thu, 19 Jul 2018 17:22:22 +0200 [thread overview]
Message-ID: <20180719152222.GD9119@lunn.ch> (raw)
In-Reply-To: <20180718161035.7005-5-brgl@bgdev.pl>
On Wed, Jul 18, 2018 at 06:10:34PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre•com>
>
> Many non-DT platforms read the MAC address from EEPROM. Usually it's
> either done with callbacks defined in board files or from SoC-specific
> ethernet drivers.
>
> In order to generalize this, try to read the MAC from nvmem in
> eth_platform_get_mac_address() using a standard lookup name:
> "mac-address".
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre•com>
> ---
> net/ethernet/eth.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> index 6b64586fd2af..adf5bd03851f 100644
> --- a/net/ethernet/eth.c
> +++ b/net/ethernet/eth.c
> @@ -54,6 +54,7 @@
> #include <linux/if_ether.h>
> #include <linux/of_net.h>
> #include <linux/pci.h>
> +#include <linux/nvmem-consumer.h>
> #include <net/dst.h>
> #include <net/arp.h>
> #include <net/sock.h>
> @@ -530,7 +531,10 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
> struct device_node *dp = dev_is_pci(dev) ?
> pci_device_to_OF_node(to_pci_dev(dev)) : dev->of_node;
> const unsigned char *addr = NULL;
> + unsigned char addrbuf[ETH_ALEN];
> + struct nvmem_cell *nvmem;
> const char *from = NULL;
> + size_t alen;
>
> if (dp) {
> addr = of_get_mac_address(dp);
> @@ -544,6 +548,31 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
> from = "arch callback";
> }
>
> + if (!addr) {
> + nvmem = nvmem_cell_get(dev, "mac-address");
> + if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EPROBE_DEFER)
How does EPROBE_DEFER work here? You say the use case is
Non-DT. Without having DT, how do you know the cell should exist, but
does not yet exist? I might be looking at old code, but i only see
-EPROBE_DEFER inside the if (np) case.
> + /* We may have a lookup registered for MAC address but
> + * the corresponding nvmem provider hasn't been
> + * registered yet.
> + */
> + return -EPROBE_DEFER;
You really should return real errors. If i'm reading
__nvmem_device_get() right, it will return a NULL pointer when the
cell does not exist. NULL is not an error, so IS_ERR() will return
false. So you should return all errors from nvmem_cell_get().
Andrew
next prev parent reply other threads:[~2018-07-19 15:22 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 16:10 [PATCH 0/5] net: extend eth_platform_get_mac_address() Bartosz Golaszewski
2018-07-18 16:10 ` [PATCH 1/5] net: visually shrink eth_platform_get_mac_address() Bartosz Golaszewski
2018-07-18 16:28 ` Andrew Lunn
2018-07-18 16:31 ` Bartosz Golaszewski
2018-07-18 23:10 ` David Miller
2018-07-18 16:10 ` [PATCH 2/5] net: add an info message to eth_platform_get_mac_address() Bartosz Golaszewski
2018-07-18 16:31 ` Andrew Lunn
2018-07-18 16:33 ` Bartosz Golaszewski
2018-07-18 23:13 ` David Miller
2018-07-18 16:10 ` [PATCH 3/5] net: fortify eth_platform_get_mac_address() Bartosz Golaszewski
2018-07-18 16:35 ` Andrew Lunn
2018-07-18 16:10 ` [PATCH 4/5] net: add support for nvmem to eth_platform_get_mac_address() Bartosz Golaszewski
2018-07-18 16:42 ` Andrew Lunn
2018-07-19 15:22 ` Andrew Lunn [this message]
2018-07-19 15:25 ` Bartosz Golaszewski
2018-07-19 17:47 ` Russell King - ARM Linux
2018-07-19 21:24 ` Bartosz Golaszewski
2018-07-19 21:48 ` Andrew Lunn
2018-07-18 16:10 ` [PATCH 5/5] net: add MTD support " Bartosz Golaszewski
2018-07-18 16:47 ` Andrew Lunn
2018-07-18 16:54 ` Bartosz Golaszewski
2018-07-18 17:03 ` Andrew Lunn
2018-07-19 8:14 ` Bartosz Golaszewski
2018-07-19 15:01 ` Andrew Lunn
2018-07-19 15:07 ` Bartosz Golaszewski
2018-07-19 15:27 ` Andrew Lunn
2018-07-19 15:35 ` Bartosz Golaszewski
2018-07-20 5:17 ` Sekhar Nori
2018-07-20 14:15 ` Andrew Lunn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180719152222.GD9119@lunn.ch \
--to=andrew@lunn$(echo .)ch \
--cc=bgolaszewski@baylibre$(echo .)com \
--cc=brgl@bgdev$(echo .)pl \
--cc=dan.carpenter@oracle$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=david@lechnology$(echo .)com \
--cc=f.fainelli@gmail$(echo .)com \
--cc=gregkh@linuxfoundation$(echo .)org \
--cc=grygorii.strashko@ti$(echo .)com \
--cc=ivan.khoronzhuk@linaro$(echo .)org \
--cc=khilman@kernel$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-omap@vger$(echo .)kernel.org \
--cc=linux@armlinux$(echo .)org.uk \
--cc=lukas@wunner$(echo .)de \
--cc=netdev@vger$(echo .)kernel.org \
--cc=nsekhar@ti$(echo .)com \
--cc=robh@kernel$(echo .)org \
--cc=srinivas.kandagatla@linaro$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox