On 06/29/2018 03:09 PM, David Lechner wrote:

On 06/29/2018 04:40 AM, Bartosz Golaszewski wrote:

quoted

From: Bartosz Golaszewski <redacted>

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 <redacted>
---
? 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 <linux/of_irq.h>
? #include <linux/of_net.h>
? #include <linux/mfd/syscon.h>
-
+#include <linux/mtd/mtd.h>
? #include <asm/irq.h>
? #include <asm/page.h>

@@ -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?

quoted

+??? 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.

quoted

+??? 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;