From f49156ea1bf3bccf45a01351cf3db2b5f6a8597e Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Tue, 26 May 2009 10:21:42 -0500 Subject: [PATCH] powerpc/qe: add polling timeout to qe_issue_cmd() The qe_issue_cmd() function (Freescale PowerPC QUICC Engine library) polls on a register until a status bit changes, but does not include a timeout to handle the situation if the bit never changes. Change the code to use the new spin_event_timeout() macro, which simplifies polling on a register without a timeout. Signed-off-by: Timur Tabi Signed-off-by: Kumar Gala --- arch/powerpc/sysdev/qe_lib/qe.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/sysdev/qe_lib/qe.c b/arch/powerpc/sysdev/qe_lib/qe.c index b28b0e512d67..237e3654f48c 100644 --- a/arch/powerpc/sysdev/qe_lib/qe.c +++ b/arch/powerpc/sysdev/qe_lib/qe.c @@ -112,6 +112,7 @@ int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input) { unsigned long flags; u8 mcn_shift = 0, dev_shift = 0; + u32 ret; spin_lock_irqsave(&qe_lock, flags); if (cmd == QE_RESET) { @@ -139,11 +140,13 @@ int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input) } /* wait for the QE_CR_FLG to clear */ - while(in_be32(&qe_immr->cp.cecr) & QE_CR_FLG) - cpu_relax(); + ret = spin_event_timeout((in_be32(&qe_immr->cp.cecr) & QE_CR_FLG) == 0, + 100, 0); + /* On timeout (e.g. failure), the expression will be false (ret == 0), + otherwise it will be true (ret == 1). */ spin_unlock_irqrestore(&qe_lock, flags); - return 0; + return ret == 1; } EXPORT_SYMBOL(qe_issue_cmd); -- GitLab