ar71xx: fix nondeterministic hangs during bootconsole/console handover
authorblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Sat, 9 Apr 2016 10:26:37 +0000 (10:26 +0000)
committerblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Sat, 9 Apr 2016 10:26:37 +0000 (10:26 +0000)
commite7b14bbfcea9227400a93e4b01225702bb966d50
tree0602c84b744c10aeee7ccef54c83560e2a61b404
parent1480b0ce2b65743778f4e9eacb61d5787d1b9723
ar71xx: fix nondeterministic hangs during bootconsole/console handover

Reconfiguring the UART when the FIFO is not empty may cause the boot to
hang. This hang is extremely suspectible to timing differences; recompiling
the kernel with the same configuration, but different UTS_VERSION
timestamps can yield images that hang more or less often. Sometimes images
are produced that hang reproducibly.

This patch should also make it into one of the next linux-stable releases,
but it's better to get this fixed as soon as possible.

Fixes #21773, #21857.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@49156 3c298f89-4303-0410-b956-a3cf2f4a3e73
target/linux/ar71xx/patches-4.1/003-MIPS-ath79-make-bootconsole-wait-for-both-THRE-and-T.patch [new file with mode: 0644]
target/linux/ar71xx/patches-4.4/003-MIPS-ath79-make-bootconsole-wait-for-both-THRE-and-T.patch [new file with mode: 0644]