Re: [PATCH] pwm: fi pwm-rz-mtu3.c build errors

[Uwe Kleine-König]

Hello,

On Mon, Jul 17, 2023 at 10:59:02PM -0700, Randy Dunlap wrote:
> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> 
> When (MFD) RZ_MTU3=m and PWM_RZ_MTU3=y, there are numerous build errors:
> 
> ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> drivers/pwm/pwm-rz-mtu3.c:374: undefined reference to `rz_mtu3_disable'
> ld: drivers/pwm/pwm-rz-mtu3.c:377: undefined reference to `rz_mtu3_8bit_ch_write'
> ld: vmlinux.o: in function `rz_mtu3_pwm_write_tgr_registers':
> drivers/pwm/pwm-rz-mtu3.c:110: undefined reference to `rz_mtu3_16bit_ch_write'
> ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> drivers/pwm/pwm-rz-mtu3.c:382: undefined reference to `rz_mtu3_8bit_ch_write'
> ld: vmlinux.o: in function `rz_mtu3_pwm_write_tgr_registers':
> drivers/pwm/pwm-rz-mtu3.c:110: undefined reference to `rz_mtu3_16bit_ch_write'
> ld: drivers/pwm/pwm-rz-mtu3.c:111: undefined reference to `rz_mtu3_16bit_ch_write'
> ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> drivers/pwm/pwm-rz-mtu3.c:397: undefined reference to `rz_mtu3_enable'
> ld: vmlinux.o: in function `rz_mtu3_pwm_disable':
> drivers/pwm/pwm-rz-mtu3.c:259: undefined reference to `rz_mtu3_8bit_ch_write'
> ld: drivers/pwm/pwm-rz-mtu3.c:264: undefined reference to `rz_mtu3_disable'
> ld: vmlinux.o: in function `rz_mtu3_pwm_enable':
> drivers/pwm/pwm-rz-mtu3.c:230: undefined reference to `rz_mtu3_8bit_ch_write'
> ld: drivers/pwm/pwm-rz-mtu3.c:234: undefined reference to `rz_mtu3_8bit_ch_write'
> ld: drivers/pwm/pwm-rz-mtu3.c:238: undefined reference to `rz_mtu3_enable'
> ld: vmlinux.o: in function `rz_mtu3_pwm_is_ch_enabled':
> drivers/pwm/pwm-rz-mtu3.c:155: undefined reference to `rz_mtu3_is_enabled'
> ld: drivers/pwm/pwm-rz-mtu3.c:162: undefined reference to `rz_mtu3_8bit_ch_read'
> ld: vmlinux.o: in function `rz_mtu3_pwm_read_tgr_registers':
> drivers/pwm/pwm-rz-mtu3.c:102: undefined reference to `rz_mtu3_16bit_ch_read'
> ld: drivers/pwm/pwm-rz-mtu3.c:102: undefined reference to `rz_mtu3_16bit_ch_read'
> ld: drivers/pwm/pwm-rz-mtu3.c:103: undefined reference to `rz_mtu3_16bit_ch_read'
> ld: vmlinux.o: in function `rz_mtu3_pwm_get_state':
> drivers/pwm/pwm-rz-mtu3.c:296: undefined reference to `rz_mtu3_8bit_ch_read'
> 
> Modify the dependencies of PWM_RZ_MTU3 so that COMPILE_TEST is
> still allowed but PWM_RZ_MTU3 depends on RZ_MTU3 if it is being built
> but also allow the latter not to be built.
> 
> Fixes: 254d3a727421 ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
> Cc: linux-pwm@xxxxxxxxxxxxxxx

While testing here I hit another (unrelated) problem:

drivers/pinctrl/renesas/pinctrl-rzg2l.c: In function ‘rzg2l_gpio_free’:
drivers/pinctrl/renesas/pinctrl-rzg2l.c:917:37: error: ‘struct gpio_chip’ has no member named ‘irq’
  917 |         virq = irq_find_mapping(chip->irq.domain, offset);
      |                                     ^~

Did someone address that one already? I guess PINCTRL_RZG2L should
select GPIOLIB_IRQCHIP. Also RZ_MTU3 should select MFD_CORE as I hit:

	aarch64-linux-gnu-ld: rz-mtu3.c:(.text+0x544): undefined reference to `mfd_remove_devices'

Commit 654c293e1687b31819f9bf1ac71b5a85a8053210 added RZ_MTU3 as bool,
and it's still bool in 254d3a72742. I think the problem started only
with b8b28b718ddd ("mfd: Add module build support for RZ/G2L MTU3a").

The patch looks fine, but the commit log needs some adaption.

The following patch would fix the build failure, too:

diff --git a/include/linux/mfd/rz-mtu3.h b/include/linux/mfd/rz-mtu3.h
index c5173bc06270..4f15c0dead60 100644
--- a/include/linux/mfd/rz-mtu3.h
+++ b/include/linux/mfd/rz-mtu3.h
@@ -151,7 +151,7 @@ struct rz_mtu3 {
 	void *priv_data;
 };
 
-#if IS_ENABLED(CONFIG_RZ_MTU3)
+#if IS_REACHABLE(CONFIG_RZ_MTU3)
 static inline bool rz_mtu3_request_channel(struct rz_mtu3_channel *ch)
 {
 	mutex_lock(&ch->lock);


maybe doing that additionally is a good idea? (Well, not entirely sure
as the above setting then would result in a non-functioning PWM driver.
Maybe that's worse than a build failure?)

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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