Re: [PATCH] powerpc/legacy_serial: check CONFIG_SERIAL_8250_CONSOLE
From: Uwe Kleine-König <hidden>
Date: 2023-06-09 08:10:20
Also in:
linux-serial, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Hello Randy, On Thu, Jun 08, 2023 at 05:33:28PM -0700, Randy Dunlap wrote:
quoted hunk ↗ jump to hunk
When SERIAL_8250_CONSOLE is not set but PPC_UDBG_16550=y, the legacy_serial code references fsl8250_handle_irq, which is only built when SERIAL_8250_CONSOLE is set. Be consistent in referencing the used CONFIG_SERIAL_8250* symbols so that the build errors do not happen. Prevents these build errors: powerpc-linux-ld: arch/powerpc/kernel/legacy_serial.o: in function `serial_dev_init': legacy_serial.c:(.init.text+0x2aa): undefined reference to `fsl8250_handle_irq' powerpc-linux-ld: legacy_serial.c:(.init.text+0x2b2): undefined reference to `fsl8250_handle_irq' Fixes: 66eff0ef528b ("powerpc/legacy_serial: Warn about 8250 devices operated without active FSL workarounds") Signed-off-by: Randy Dunlap <redacted> Cc: Uwe Kleine-König <redacted> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <redacted> Cc: linuxppc-dev@lists.ozlabs.org --- arch/powerpc/kernel/legacy_serial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -- a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c--- a/arch/powerpc/kernel/legacy_serial.c +++ b/arch/powerpc/kernel/legacy_serial.c@@ -508,9 +508,9 @@ static void __init fixup_port_irq(int in port->irq = virq; - if (IS_ENABLED(CONFIG_SERIAL_8250) && + if (IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE) && of_device_is_compatible(np, "fsl,ns16550")) { - if (IS_REACHABLE(CONFIG_SERIAL_8250)) { + if (IS_REACHABLE(CONFIG_SERIAL_8250_CONSOLE)) { port->handle_irq = fsl8250_handle_irq; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); } else {
Argh, indeed there is a problem. Your patch however defeats the idea of 66eff0ef528b[1] which is still valid. And with your patch the else branch that starts at the end of the above hunk is never taken. With the feedback I got on https://lore.kernel.org/linux-serial/20230605130857.85543-3-u.kleine-koenig@pengutronix.de (local) the probable outcome is that CONFIG_SERIAL_8250_FSL becomes tristate and so the fix that is more future proof and keeps the warning, looks as follows:
diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index fdbd85aafeb1..6ee65741dbd5 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c@@ -510,7 +510,7 @@ static void __init fixup_port_irq(int index, if (IS_ENABLED(CONFIG_SERIAL_8250) && of_device_is_compatible(np, "fsl,ns16550")) { - if (IS_REACHABLE(CONFIG_SERIAL_8250)) { + if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) { port->handle_irq = fsl8250_handle_irq; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); } else {
This should to the right thing now (while CONFIG_SERIAL_8250_FSL is still bool and only on if CONFIG_SERIAL_8250 is =y) and also once CONFIG_SERIAL_8250_FSL can be =m (which would make fsl8250_handle_irq not available for powerpc platform code). But given that I screwed this up several times now, I will think about this some more and do some more tests before submitting that as a proper patch. Best regards Uwe [1] Warn if the 8250 device is used but the required FSL workarounds are not. -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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