Messages in this thread Patch in this message | | | Date | Sun, 18 Jul 2004 11:35:35 -0400 | From | David Eger <> | Subject | [PATCH] pmac_zilog: serial minors taken failure path fix (resend/combined) |
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Dear Linus,
It turns out that the pmac_zilog fix just patched over the symptom of a bad failure path. Please apply this to properly fix the problem. There are three patches (and a more lengthy explanation) of this over in the pmac_zilog thread:
+ one to fix the dev major/minor is taken failure path + one to patch the patch (stupid mistake), and + one to restore the default ppc config to what it had been (apologies to Hollis and trini)
Here are all three combined for your convenience.
-dte
I've tracked down the core issue giving me the oops wrt pmac_zilog.
When you have two serial drivers, (e.g. 8250 and PMAC_ZILOG) they both say
"I want to reserve X ports starting with major TTY_MAJOR and minor 64".
By the time pmac_zilog gets there, the ports it requests are already reserved. Unfortunately, init_pmz() doesn't check for pmz_register() failure, and so it merrily goes on to register the half-initialized pmac_zilog driver with the power management subsystem.
This path provides a proper failure path.
Also:
Restore ppc configs now that I know people use AT Keyboards on CHRP and PReP machines, and the zilog driver is no longer Oops'ing.
Signed-off-by: David Eger <eger@havoc.gtf.org>
diff -Nru a/arch/ppc/defconfig b/arch/ppc/defconfig --- a/arch/ppc/defconfig 2004-07-18 11:29:40 -04:00 +++ b/arch/ppc/defconfig 2004-07-18 11:29:41 -04:00 @@ -689,7 +689,7 @@ # Input Device Drivers # CONFIG_INPUT_KEYBOARD=y -# CONFIG_KEYBOARD_ATKBD is not set +CONFIG_KEYBOARD_ATKBD=y # CONFIG_KEYBOARD_SUNKBD is not set # CONFIG_KEYBOARD_LKKBD is not set # CONFIG_KEYBOARD_XTKBD is not set @@ -724,8 +724,8 @@ # # Non-8250 serial port support # -# CONFIG_SERIAL_CORE is not set -# CONFIG_SERIAL_PMACZILOG is not set +CONFIG_SERIAL_CORE=y +CONFIG_SERIAL_PMACZILOG=y # CONFIG_SERIAL_PMACZILOG_CONSOLE is not set CONFIG_UNIX98_PTYS=y CONFIG_LEGACY_PTYS=y diff -Nru a/drivers/serial/pmac_zilog.c b/drivers/serial/pmac_zilog.c --- a/drivers/serial/pmac_zilog.c 2004-07-18 11:29:40 -04:00 +++ b/drivers/serial/pmac_zilog.c 2004-07-18 11:29:40 -04:00 @@ -1433,6 +1433,7 @@ ioremap(np->addrs[np->n_addrs - 1].address, 0x1000); if (uap->rx_dma_regs == NULL) { iounmap((void *)uap->tx_dma_regs); + uap->tx_dma_regs = NULL; uap->flags &= ~PMACZILOG_FLAG_HAS_DMA; goto no_dma; } @@ -1490,7 +1491,6 @@ uap->port.ops = &pmz_pops; uap->port.type = PORT_PMAC_ZILOG; uap->port.flags = 0; - spin_lock_init(&uap->port.lock); /* Setup some valid baud rate information in the register * shadows so we don't write crap there before baud rate is @@ -1508,10 +1508,13 @@ { struct device_node *np; - iounmap((void *)uap->control_reg); np = uap->node; + iounmap((void *)uap->rx_dma_regs); + iounmap((void *)uap->tx_dma_regs); + iounmap((void *)uap->control_reg); uap->node = NULL; of_node_put(np); + memset(uap, 0, sizeof(struct uart_pmac_port)); } /* @@ -1798,7 +1801,7 @@ * Register this driver with the serial core */ rc = uart_register_driver(&pmz_uart_reg); - if (rc != 0) + if (rc) return rc; /* @@ -1808,10 +1811,19 @@ struct uart_pmac_port *uport = &pmz_ports[i]; /* NULL node may happen on wallstreet */ if (uport->node != NULL) - uart_add_one_port(&pmz_uart_reg, &uport->port); + rc = uart_add_one_port(&pmz_uart_reg, &uport->port); + if (rc) + goto err_out; } return 0; +err_out: + while (i-- > 0) { + struct uart_pmac_port *uport = &pmz_ports[i]; + uart_remove_one_port(&pmz_uart_reg, &uport->port); + } + uart_unregister_driver(&pmz_uart_reg); + return rc; } static struct of_match pmz_match[] = @@ -1841,6 +1853,7 @@ static int __init init_pmz(void) { + int rc, i; printk(KERN_INFO "%s\n", version); /* @@ -1862,7 +1875,16 @@ /* * Now we register with the serial layer */ - pmz_register(); + rc = pmz_register(); + if (rc) { + printk(KERN_ERR + "pmac_zilog: Error registering serial device, disabling pmac_zilog.\n" + "pmac_zilog: Did another serial driver already claim the minors?\n"); + /* effectively "pmz_unprobe()" */ + for (i=0; i < pmz_ports_count; i++) + pmz_dispose_port(&pmz_ports[i]); + return rc; + } /* * Then we register the macio driver itself - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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