[PATCH] m68k: Fix WARNING splat in pmac_zilog driver
Geert Uytterhoeven
geert at linux-m68k.org
Fri Nov 20 18:46:51 AEDT 2020
Hi Finn,
On Fri, Nov 20, 2020 at 5:51 AM Finn Thain <fthain at telegraphics.com.au> wrote:
> Don't add platform resources that won't be used. This avoids a
> recently-added warning from the driver core, that can show up on a
> multi-platform kernel when !MACH_IS_MAC.
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 0 at drivers/base/platform.c:224 platform_get_irq_optional+0x8e/0xce
> 0 is an invalid IRQ number
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper Not tainted 5.9.0-multi #1
> Stack from 004b3f04:
> 004b3f04 00462c2f 00462c2f 004b3f20 0002e128 004754db 004b6ad4 004b3f4c
> 0002e19c 004754f7 000000e0 00285ba0 00000009 00000000 004b3f44 ffffffff
> 004754db 004b3f64 004b3f74 00285ba0 004754f7 000000e0 00000009 004754db
> 004fdf0c 005269e2 004fdf0c 00000000 004b3f88 00285cae 004b6964 00000000
> 004fdf0c 004b3fac 0051cc68 004b6964 00000000 004b6964 00000200 00000000
> 0051cc3e 0023c18a 004b3fc0 0051cd8a 004fdf0c 00000002 0052b43c 004b3fc8
> Call Trace: [<0002e128>] __warn+0xa6/0xd6
> [<0002e19c>] warn_slowpath_fmt+0x44/0x76
> [<00285ba0>] platform_get_irq_optional+0x8e/0xce
> [<00285ba0>] platform_get_irq_optional+0x8e/0xce
> [<00285cae>] platform_get_irq+0x12/0x4c
> [<0051cc68>] pmz_init_port+0x2a/0xa6
> [<0051cc3e>] pmz_init_port+0x0/0xa6
> [<0023c18a>] strlen+0x0/0x22
> [<0051cd8a>] pmz_probe+0x34/0x88
> [<0051cde6>] pmz_console_init+0x8/0x28
> [<00511776>] console_init+0x1e/0x28
> [<0005a3bc>] printk+0x0/0x16
> [<0050a8a6>] start_kernel+0x368/0x4ce
> [<005094f8>] _sinittext+0x4f8/0xc48
> random: get_random_bytes called from print_oops_end_marker+0x56/0x80 with crng_init=0
> ---[ end trace 392d8e82eed68d6c ]---
>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Joshua Thompson <funaho at jurai.org>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby at kernel.org>
> Cc: stable at vger.kernel.org # v5.8+
> References: commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
> Reported-by: Laurent Vivier <laurent at vivier.eu>
> Signed-off-by: Finn Thain <fthain at telegraphics.com.au>
> ---
> The global platform_device structs provide the equivalent of a direct
> search of the OpenFirmware tree, for platforms that don't have OF.
> The purpose of that search is discussed in the comments in pmac_zilog.c:
>
> * First, we need to do a direct OF-based probe pass. We
> * do that because we want serial console up before the
> * macio stuffs calls us back
>
> The actual platform bus matching takes place later, with a module_initcall,
> following the usual pattern.
I think it would be good for this explanation to be part of the
actual patch description above.
> --- a/arch/m68k/mac/config.c
> +++ b/arch/m68k/mac/config.c
> @@ -777,16 +777,12 @@ static struct resource scc_b_rsrcs[] = {
> struct platform_device scc_a_pdev = {
> .name = "scc",
> .id = 0,
> - .num_resources = ARRAY_SIZE(scc_a_rsrcs),
> - .resource = scc_a_rsrcs,
> };
> EXPORT_SYMBOL(scc_a_pdev);
>
> struct platform_device scc_b_pdev = {
> .name = "scc",
> .id = 1,
> - .num_resources = ARRAY_SIZE(scc_b_rsrcs),
> - .resource = scc_b_rsrcs,
> };
> EXPORT_SYMBOL(scc_b_pdev);
>
> @@ -813,10 +809,15 @@ static void __init mac_identify(void)
>
> /* Set up serial port resources for the console initcall. */
>
> - scc_a_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase + 2;
> - scc_a_rsrcs[0].end = scc_a_rsrcs[0].start;
> - scc_b_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase;
> - scc_b_rsrcs[0].end = scc_b_rsrcs[0].start;
> + scc_a_rsrcs[0].start = (resource_size_t)mac_bi_data.sccbase + 2;
> + scc_a_rsrcs[0].end = scc_a_rsrcs[0].start;
> + scc_a_pdev.num_resources = ARRAY_SIZE(scc_a_rsrcs);
> + scc_a_pdev.resource = scc_a_rsrcs;
> +
> + scc_b_rsrcs[0].start = (resource_size_t)mac_bi_data.sccbase;
> + scc_b_rsrcs[0].end = scc_b_rsrcs[0].start;
> + scc_b_pdev.num_resources = ARRAY_SIZE(scc_b_rsrcs);
> + scc_b_pdev.resource = scc_b_rsrcs;
>
> switch (macintosh_config->scc_type) {
> case MAC_SCC_PSC:
> diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
> index 96e7aa479961..95abdb305d67 100644
> --- a/drivers/tty/serial/pmac_zilog.c
> +++ b/drivers/tty/serial/pmac_zilog.c
> @@ -1697,18 +1697,17 @@ extern struct platform_device scc_a_pdev, scc_b_pdev;
>
> static int __init pmz_init_port(struct uart_pmac_port *uap)
> {
> - struct resource *r_ports;
> - int irq;
> + struct resource *r_ports, *r_irq;
>
> r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
> - irq = platform_get_irq(uap->pdev, 0);
> - if (!r_ports || irq <= 0)
> + r_irq = platform_get_resource(uap->pdev, IORESOURCE_IRQ, 0);
> + if (!r_ports || !r_irq)
> return -ENODEV;
>
> uap->port.mapbase = r_ports->start;
> uap->port.membase = (unsigned char __iomem *) r_ports->start;
> uap->port.iotype = UPIO_MEM;
> - uap->port.irq = irq;
> + uap->port.irq = r_irq->start;
> uap->port.uartclk = ZS_CLOCK;
> uap->port.fifosize = 1;
> uap->port.ops = &pmz_pops;
Given the resources are no longer present on !MAC, just doing
r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
+ if (!r_ports)
+ return -ENODEV;
irq = platform_get_irq(uap->pdev, 0);
should be sufficient?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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