This patch ensures that if a particular uart clock node was not acquired then do not proceed with enabling clock and device registration for that uart.
Without this patch if uart_ick/fck value was null then it throw oops as below and boot will halt. <1>Unable to handle kernel NULL pointer dereference at virtual address 0000001c <1>pgd = c0004000 <1>[0000001c] *pgd=00000000 <0>Internal error: Oops: 5 [#1] <0>last sysfs file: <d>Modules linked in: CPU: 0 Not tainted (2.6.34-rc3-00006-g7da06f1-dirty #15) PC is at omap_serial_init_port+0x64/0x3a0 LR is at 0x8 pc : [<c000f51c>] lr : [<00000008>] psr: 60000013 sp : dfc2bf80 ip : 00000000 fp : 00000000 r10: 000007c8 r9 : c05c65f8 r8 : 00000000 r7 : c05c6dc0 r6 : c000b44c r5 : 00000000 r4 : 00000004 r3 : 00000007 r2 : c05c6538 r1 : fb020000 r0 : c05c6dc0 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387f Table: 80004019 DAC: 00000017 <0>Process swapper (pid: 1, stack limit = 0xdfc2a2f0) <0>Stack: (0xdfc2bf80 to 0xdfc2c000) <0>bf80: 00000003 fb020000 00000004 00000000 c000b44c 00000000 00000000 00000000 <0>bfa0: 00000000 c000f880 c002e288 c00135e0 c002e288 c00137f4 c002e288 c000b464 <0>bfc0: c002e288 c003e34c 00000031 00000000 00000000 00000192 00000000 c002e288 <0>bfe0: 00000000 00000000 00000000 c0008578 00000000 c003f970 ffffffff ffffffff [<c000f51c>] (omap_serial_init_port+0x64/0x3a0) from [<c000f880>] (omap_serial_init+0x28/0x3c) [<c000f880>] (omap_serial_init+0x28/0x3c) from [<c00135e0>] (zoom_peripherals_init+0x44/0x6c) [<c00135e0>] (zoom_peripherals_init+0x44/0x6c) from [<c00137f4>] (omap_sdp_init+0x14/0x54) [<c00137f4>] (omap_sdp_init+0x14/0x54) from [<c000b464>] (customize_machine+0x18/0x24) [<c000b464>] (customize_machine+0x18/0x24) from [<c003e34c>] (do_one_initcall+0x5c/0x1b8) [<c003e34c>] (do_one_initcall+0x5c/0x1b8) from [<c0008578>] (kernel_init+0x90/0x144) [<c0008578>] (kernel_init+0x90/0x144) from [<c003f970>] (kernel_thread_exit+0x0/0x8) <0>Code: eb00ef8f e597c06c e3a0e008 e3a03007 (e5dc201c) <4>---[ end trace 1b75b31a2719ed1c ]--- <0>Kernel panic - not syncing: Attempted to kill init! Cc: Tony Lindgren <[email protected]> Cc: Kevin Hilman <[email protected]> Reported-by: Venkatraman S <[email protected]> Signed-off-by: Govindraj.R <[email protected]> --- arch/arm/mach-omap2/serial.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c index da77930..6d21872 100644 --- a/arch/arm/mach-omap2/serial.c +++ b/arch/arm/mach-omap2/serial.c @@ -727,6 +727,14 @@ void __init omap_serial_init_port(int port) pdev = &uart->pdev; dev = &pdev->dev; + /* + * If clock nodes where not acquired + * then do not proceed with enabling + * clocks and device registration. + */ + if (!uart->fck || !uart->ick) + return; + omap_uart_enable_clocks(uart); omap_uart_reset(uart); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
