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>
This commit is contained in:
Timur Tabi 2009-05-26 10:21:42 -05:00 committed by Kumar Gala
parent b71a107c66
commit f49156ea1b

View File

@ -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);