From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lechner Subject: Re: [PATCH v4 08/18] net: davinci_emac: potentially get the MAC address from MTD Date: Fri, 29 Jun 2018 15:35:27 -0500 Message-ID: References: <20180629094039.7543-1-brgl@bgdev.pl> <20180629094039.7543-9-brgl@bgdev.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, netdev@vger.kernel.org, Bartosz Golaszewski To: Bartosz Golaszewski , Sekhar Nori , Kevin Hilman , Russell King , Grygorii Strashko , "David S . Miller" , Srinivas Kandagatla , Lukas Wunner , Rob Herring , Florian Fainelli , Dan Carpenter , Ivan Khoronzhuk , Greg Kroah-Hartman , Andrew Lunn , Jonathan Corbet Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 06/29/2018 03:09 PM, David Lechner wrote: > On 06/29/2018 04:40 AM, Bartosz Golaszewski wrote: >> From: Bartosz Golaszewski >> >> On da850-evm board we can read the MAC address from MTD. It's currently >> done in the relevant board file, but we want to get rid of all the MAC >> reading callbacks from the board file (SPI and NAND). Move the reading >> of the MAC address from SPI to the emac driver's probe function. >> >> Signed-off-by: Bartosz Golaszewski >> --- >>   drivers/net/ethernet/ti/davinci_emac.c | 20 ++++++++++++++++++-- >>   1 file changed, 18 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c >> index a1a6445b5a7e..48e6a7755811 100644 >> --- a/drivers/net/ethernet/ti/davinci_emac.c >> +++ b/drivers/net/ethernet/ti/davinci_emac.c >> @@ -67,7 +67,7 @@ >>   #include >>   #include >>   #include >> - >> +#include >>   #include >>   #include >> @@ -1783,7 +1783,10 @@ static int davinci_emac_probe(struct platform_device *pdev) >>       struct cpdma_params dma_params; >>       struct clk *emac_clk; >>       unsigned long emac_bus_frequency; >> - >> +#ifdef CONFIG_MTD >> +    size_t mac_addr_len; >> +    struct mtd_info *mtd; >> +#endif /* CONFIG_MTD */ >>       /* obtain emac clock from kernel */ >>       emac_clk = devm_clk_get(&pdev->dev, NULL); >> @@ -1815,6 +1818,19 @@ static int davinci_emac_probe(struct platform_device *pdev) >>           goto err_free_netdev; >>       } >> +#ifdef CONFIG_MTD > > What about the case when MTD is compiled as a module? > >> +    mtd = get_mtd_device_nm("MAC-Address"); > > What about the case when PTR_ERR(mtd) == -EPROBE_DEFER? To answer my own question: because get_mtd_device_nm() doesn't ever return -EPROBE_DEFER. I'm trying to make this work on LCDK, but the emac driver probes before any mtd device is registered, so, I just get -ENODEV even though I've added a partition to the device tree labeled "MAC-Address". You can see in the kernel messages that MTD is not probed until later. > >> +    if (!IS_ERR(mtd)) { >> +        rc = mtd_read(mtd, 0, ETH_ALEN, >> +                  &mac_addr_len, priv->mac_addr); >> +        if (rc == 0) >> +            dev_info(&pdev->dev, >> +                 "Read MAC addr from SPI Flash: %pM\n", >> +                 priv->mac_addr); >> +        put_mtd_device(mtd); >> +    } >> +#endif /* CONFIG_MTD */ >> + >>       /* MAC addr and PHY mask , RMII enable info from platform_data */ >>       memcpy(priv->mac_addr, pdata->mac_addr, ETH_ALEN); >>       priv->phy_id = pdata->phy_id; >> >