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authorFeng Tang <feng.tang@intel.com>2018-10-02 19:49:21 +0300
committerBorislav Petkov <bp@suse.de>2018-10-02 22:02:47 +0300
commitd2266bbfa9e3e32e3b642965088ca461bd24a94f (patch)
tree14f22dd9237f9679d6cdd7408144afebaf5764c1 /Documentation/admin-guide
parent17b57b1883c1285f3d0dc2266e8f79286a7bef38 (diff)
downloadlinux-d2266bbfa9e3e32e3b642965088ca461bd24a94f.tar.xz
x86/earlyprintk: Add a force option for pciserial device
The "pciserial" earlyprintk variant helps much on many modern x86 platforms, but unfortunately there are still some platforms with PCI UART devices which have the wrong PCI class code. In that case, the current class code check does not allow for them to be used for logging. Add a sub-option "force" which overrides the class code check and thus the use of such device can be enforced. [ bp: massage formulations. ] Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Stuart R . Anderson" <stuart.r.anderson@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H Peter Anvin <hpa@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thymo van Beers <thymovanbeers@gmail.com> Cc: alan@linux.intel.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20181002164921.25833-1-feng.tang@intel.com
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt6
1 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 92eb1f42240d..34e6800dea0e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1063,7 +1063,7 @@
earlyprintk=serial[,0x...[,baudrate]]
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
- earlyprintk=pciserial,bus:device.function[,baudrate]
+ earlyprintk=pciserial[,force],bus:device.function[,baudrate]
earlyprintk=xdbc[xhciController#]
earlyprintk is useful when the kernel crashes before
@@ -1095,6 +1095,10 @@
The sclp output can only be used on s390.
+ The optional "force" to "pciserial" enables use of a
+ PCI device even when its classcode is not of the
+ UART class.
+
edac_report= [HW,EDAC] Control how to report EDAC event
Format: {"on" | "off" | "force"}
on: enable EDAC to report H/W event. May be overridden