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.fe...@microchip.com wrote:

On 24/06/2019 at 08:16, Palmer Dabbelt wrote:

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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 <pal...@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