Messages in this thread Patch in this message | | | Subject | Re: Regression in 4.9-rc1 for PPC32 - bisected to commit 05fd007e4629 | From | Larry Finger <> | Date | Mon, 24 Oct 2016 20:30:43 -0500 |
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I have a hack that works. Perhaps it will give a bit more understanding so that a proper patch can be created. My changes were applied on top of 4.9-rc1 with the patch from https://www.linux-mips.org/archives/linux-mips/2016-10/msg00130.html, and were as follows:
Index: linux/kernel/printk/printk.c =================================================================== --- linux.orig/kernel/printk/printk.c 2016-10-24 12:29:17.838938604 -0500 +++ linux/kernel/printk/printk.c 2016-10-24 19:31:20.012593000 -0500 @@ -2657,7 +2657,9 @@ * didn't select a console we take the first one * that registers here. */ - if (preferred_console < 0 && !of_specified_console) { + pr_info("Before: newcon->device %p, newcon->setup %p\n", newcon->device, newcon->setup); + if ((preferred_console < 0 && !of_specified_console) || + !newcon->setup) { if (newcon->index < 0) newcon->index = 0; if (newcon->setup == NULL || @@ -2670,6 +2672,7 @@ } }
+ pr_info("After: newcon->device %p, newcon->setup %p\n", newcon->device, newcon->setup); /* * See if this console matches one we selected on * the command line. The changes in commit 05fd007e4629 prevent the body of the 'if ((preferred_console < 0 ...' loop from ever being executed; however, the failure indicates that we do need to go through this code at least once. I tested various quantities, and !newcon->setup was the only one that helped.
The outputs from the pr_info statements above and the changes in console as shown by 'dmesg | egrep "console|newcon" are: [ 0.000000] Before: newcon->device (null), newcon->setup (null) Part of the body of if executed [ 0.000000] After: newcon->device (null), newcon->setup (null) [ 0.000000] bootconsole [udbg0] enabled [ 0.001581] Before: newcon->device c0326e34, newcon->setup (null) We now have newcon->device set, Part of body of if executed [ 0.001934] After: newcon->device c0326e34, newcon->setup (null) [ 0.002285] console [tty0] enabled [ 0.002595] bootconsole [udbg0] disabled [ 0.002913] Before: newcon->device c032cc4c, newcon->setup c032cc80 This time the body of if is not executed and will not be executed anymore. [ 0.002925] After: newcon->device c032cc4c, newcon->setup c032cc80 [ 0.002943] Before: newcon->device c0331ad8, newcon->setup c0331c34 [ 0.002956] After: newcon->device c0331ad8, newcon->setup c0331c34 [ 0.003060] Before: newcon->device c0331ad8, newcon->setup c068dbc8 [ 0.003074] After: newcon->device c0331ad8, newcon->setup c068dbc8 [ 0.003322] Before: newcon->device c0331ad8, newcon->setup c068ddc4 [ 0.003335] After: newcon->device c0331ad8, newcon->setup c068ddc4 [ 1.993661] Before: newcon->device c0331ad8, newcon->setup c068dbc8 [ 1.993759] After: newcon->device c0331ad8, newcon->setup c068dbc8 [ 1.994395] Before: newcon->device c0331ad8, newcon->setup c068dbc8 [ 1.994492] After: newcon->device c0331ad8, newcon->setup c068dbc8 Larry
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