Re: [PATCH 1/2] net: macb: Fix compilation on systems without COMMON_CLK

[Palmer Dabbelt]

On Mon, 24 Jun 2019 02:40:21 PDT (-0700), Nicolas.Ferre@xxxxxxxxxxxxx wrote:
> On 24/06/2019 at 08:16, Palmer Dabbelt wrote:
> > External E-Mail
> >
> >
> > The patch to add support for the FU540-C000 added a dependency on
> > COMMON_CLK, but didn't express that via Kconfig.  This fixes the build
> > failure by adding CONFIG_MACB_FU540, which depends on COMMON_CLK and
> > conditionally enables the FU540-C000 support.
>
> Let's try to limit the use of  #ifdef's throughout the code. We are 
> using them in this driver but only for the hot paths and things that 
> have an impact on performance. I don't think it's the case here: so 
> please find another option => NACK.

OK.  Would you accept adding a Kconfig dependency of the generic MACB driver on
COMMON_CLK, as suggested in the cover letter?

> > I've built this with a powerpc allyesconfig (which pointed out the bug)
> > and on RISC-V, manually checking to ensure the code was built.  I
> > haven't even booted the resulting kernels.
> >
> > Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000")
> > Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxx>
> > ---
> >   drivers/net/ethernet/cadence/Kconfig     | 11 +++++++++++
> >   drivers/net/ethernet/cadence/macb_main.c | 12 ++++++++++++
> >   2 files changed, 23 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/cadence/Kconfig b/drivers/net/ethernet/cadence/Kconfig
> > index 1766697c9c5a..74ee2bfd2369 100644
> > --- a/drivers/net/ethernet/cadence/Kconfig
> > +++ b/drivers/net/ethernet/cadence/Kconfig
> > @@ -40,6 +40,17 @@ config MACB_USE_HWSTAMP
> >   	---help---
> >   	  Enable IEEE 1588 Precision Time Protocol (PTP) support for MACB.
> >   
> > +config MACB_FU540
> > +	bool "Enable support for the SiFive FU540 clock controller"
> > +	depends on MACB && COMMON_CLK
> > +	default y
> > +	---help---
> > +	  Enable support for the MACB/GEM clock controller on the SiFive
> > +	  FU540-C000.  This device is necessary for switching between 10/100
> > +	  and gigabit modes on the FU540-C000 SoC, without which it is only
> > +	  possible to bring up the Ethernet link in whatever mode the
> > +	  bootloader probed.
> > +
> >   config MACB_PCI
> >   	tristate "Cadence PCI MACB/GEM support"
> >   	depends on MACB && PCI && COMMON_CLK
> > diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> > index c545c5b435d8..a903dfdd4183 100644
> > --- a/drivers/net/ethernet/cadence/macb_main.c
> > +++ b/drivers/net/ethernet/cadence/macb_main.c
> > @@ -41,6 +41,7 @@
> >   #include <linux/pm_runtime.h>
> >   #include "macb.h"
> >   
> > +#ifdef CONFIG_MACB_FU540
> >   /* This structure is only used for MACB on SiFive FU540 devices */
> >   struct sifive_fu540_macb_mgmt {
> >   	void __iomem *reg;
> > @@ -49,6 +50,7 @@ struct sifive_fu540_macb_mgmt {
> >   };
> >   
> >   static struct sifive_fu540_macb_mgmt *mgmt;
> > +#endif
> >   
> >   #define MACB_RX_BUFFER_SIZE	128
> >   #define RX_BUFFER_MULTIPLE	64  /* bytes */
> > @@ -3956,6 +3958,7 @@ static int at91ether_init(struct platform_device *pdev)
> >   	return 0;
> >   }
> >   
> > +#ifdef CONFIG_MACB_FU540
> >   static unsigned long fu540_macb_tx_recalc_rate(struct clk_hw *hw,
> >   					       unsigned long parent_rate)
> >   {
> > @@ -4056,7 +4059,9 @@ static int fu540_c000_init(struct platform_device *pdev)
> >   
> >   	return macb_init(pdev);
> >   }
> > +#endif
> >   
> > +#ifdef CONFIG_MACB_FU540
> >   static const struct macb_config fu540_c000_config = {
> >   	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO |
> >   		MACB_CAPS_GEM_HAS_PTP,
> > @@ -4065,6 +4070,7 @@ static const struct macb_config fu540_c000_config = {
> >   	.init = fu540_c000_init,
> >   	.jumbo_max_len = 10240,
> >   };
> > +#endif
> >   
> >   static const struct macb_config at91sam9260_config = {
> >   	.caps = MACB_CAPS_USRIO_HAS_CLKEN | MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII,
> > @@ -4155,7 +4161,9 @@ static const struct of_device_id macb_dt_ids[] = {
> >   	{ .compatible = "cdns,emac", .data = &emac_config },
> >   	{ .compatible = "cdns,zynqmp-gem", .data = &zynqmp_config},
> >   	{ .compatible = "cdns,zynq-gem", .data = &zynq_config },
> > +#ifdef CONFIG_MACB_FU540
> >   	{ .compatible = "sifive,fu540-macb", .data = &fu540_c000_config },
> > +#endif
> >   	{ /* sentinel */ }
> >   };
> >   MODULE_DEVICE_TABLE(of, macb_dt_ids);
> > @@ -4363,7 +4371,9 @@ static int macb_probe(struct platform_device *pdev)
> >   
> >   err_disable_clocks:
> >   	clk_disable_unprepare(tx_clk);
> > +#ifdef CONFIG_MACB_FU540
> >   	clk_unregister(tx_clk);
> > +#endif
> >   	clk_disable_unprepare(hclk);
> >   	clk_disable_unprepare(pclk);
> >   	clk_disable_unprepare(rx_clk);
> > @@ -4398,7 +4408,9 @@ static int macb_remove(struct platform_device *pdev)
> >   		pm_runtime_dont_use_autosuspend(&pdev->dev);
> >   		if (!pm_runtime_suspended(&pdev->dev)) {
> >   			clk_disable_unprepare(bp->tx_clk);
> > +#ifdef CONFIG_MACB_FU540
> >   			clk_unregister(bp->tx_clk);
> > +#endif
> >   			clk_disable_unprepare(bp->hclk);
> >   			clk_disable_unprepare(bp->pclk);
> >   			clk_disable_unprepare(bp->rx_clk);
>
>
> --
> Nicolas Ferre