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

[<Nicolas.Ferre@microchip.com>]

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.

> 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@sifive.com>
> ---
>   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