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 <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/sysdev/qe_lib/qe.c b/arch/powerpc/sysdev/qe_lib/qe.c
index b28b0e5..237e365 100644
--- a/arch/powerpc/sysdev/qe_lib/qe.c
+++ b/arch/powerpc/sysdev/qe_lib/qe.c
@@ -112,6 +112,7 @@
{
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 @@
}
/* 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);