From: Rajmohan Mani Date: Wed, 18 Nov 2015 08:48:20 +0000 (+0200) Subject: xhci: Workaround to get Intel xHCI reset working more reliably X-Git-Tag: v3.2.75~61 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18fb47eeecd9103959e70700fdf0b2b392d8ab0e;p=pandora-kernel.git xhci: Workaround to get Intel xHCI reset working more reliably commit a5964396190d0c40dd549c23848c282fffa5d1f2 upstream. Existing Intel xHCI controllers require a delay of 1 mS, after setting the CMD_RESET bit in command register, before accessing any HC registers. This allows the HC to complete the reset operation and be ready for HC register access. Without this delay, the subsequent HC register access, may result in a system hang, very rarely. Verified CherryView / Braswell platforms go through over 5000 warm reboot cycles (which was not possible without this patch), without any xHCI reset hang. Signed-off-by: Rajmohan Mani Tested-by: Joe Lawrence Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed