[PATCH] RapidIO: Fix hang on RapidIO doorbell queue full condition

Thomas Taranowski tom at baringforge.com
Tue Jan 4 18:29:47 EST 2011

In fsl_rio_dbell_handler, the code currently simply acknowledges the QFI queue
full interrupt, but does nothing to resolve the queue full condition.  Instead,
it jumps to the end of the isr.  When a queue full condition occurs, the isr is
then re-entered immediately and continually, forever.

The fix is to just fall through and read out current doorbell entries.

Tested against 2.6.26-rc8 on a p2020

Signed-off-by: Thomas Taranowski <tom at baringforge.com>
 arch/powerpc/sysdev/fsl_rio.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index 9725369..9f99bef 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -973,7 +973,6 @@ fsl_rio_dbell_handler(int irq, void *dev_instance)
        if (dsr & DOORBELL_DSR_QFI) {
                pr_info("RIO: doorbell queue full\n");
                out_be32(&priv->msg_regs->dsr, DOORBELL_DSR_QFI);
-               goto out;

        /* XXX Need to check/dispatch until queue empty */

Thomas Taranowski
Certified netburner consultant

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