Re: [PATCH] net: phy: add driver for Motorcomm yt8511 phy

On Wed, May 19, 2021 at 12:37:43PM +0200, Heiner Kallweit wrote:

On 19.05.2021 10:18, Leon Romanovsky wrote:

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On Tue, May 18, 2021 at 08:20:03PM -0400, Peter Geis wrote:

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On Tue, May 18, 2021 at 4:59 AM Leon Romanovsky [off-list ref] wrote:

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On Tue, May 11, 2021 at 05:46:06PM -0400, Peter Geis wrote:

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Add a driver for the Motorcomm yt8511 phy that will be used in the
production Pine64 rk3566-quartz64 development board.
It supports gigabit transfer speeds, rgmii, and 125mhz clk output.

Signed-off-by: Peter Geis <redacted>
---
 MAINTAINERS                 |  6 +++
 drivers/net/phy/Kconfig     |  6 +++
 drivers/net/phy/Makefile    |  1 +
 drivers/net/phy/motorcomm.c | 85 +++++++++++++++++++++++++++++++++++++
 4 files changed, 98 insertions(+)
 create mode 100644 drivers/net/phy/motorcomm.c

<...>

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+static const struct mdio_device_id __maybe_unused motorcomm_tbl[] = {
+     { PHY_ID_MATCH_EXACT(PHY_ID_YT8511) },
+     { /* sentinal */ }
+}

Why is this "__maybe_unused"? This *.c file doesn't have any compilation option
to compile part of it.

The "__maybe_unused" is not needed in this case.

I was simply following convention, for example the realtek.c,
micrel.c, and smsc.c drivers all have this as well.

Maybe they have a reason, but this specific driver doesn't have such.

It's used like this:
MODULE_DEVICE_TABLE(mdio, <mdio_device_id_tbl>);

And MODULE_DEVICE_TABLE is a no-op if MODULE isn't defined:

#ifdef MODULE
/* Creates an alias so file2alias.c can find device table. */
#define MODULE_DEVICE_TABLE(type, name)					\
extern typeof(name) __mod_##type##__##name##_device_table		\
  __attribute__ ((unused, alias(__stringify(name))))
#else  /* !MODULE */
#define MODULE_DEVICE_TABLE(type, name)
#endif

In this case the table is unused.

Do you see compilation warning for such scenario?

Thanks

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Thanks

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Thanks