diff mbox series

[3/4] soc/fsl/qbman: Use last response to determine valid bit

Message ID 1537456011-10769-4-git-send-email-madalin.bucur@nxp.com (mailing list archive)
State Not Applicable
Headers show
Series soc/fsl/qbman: DPAA QBMan fixes and additions | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success next/apply_patch Successfully applied
snowpatch_ozlabs/checkpatch warning Test checkpatch on branch next

Commit Message

Madalin Bucur Sept. 20, 2018, 3:06 p.m. UTC 
From: Roy Pledge <roy.pledge@nxp.com>

Use the last valid response when determining what valid bit
to use next for management commands. This is needed in the
case that the portal was previously used by other software
like a bootloader or if the kernel is restarted without a
hardware reset.

Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
---
 drivers/soc/fsl/qbman/qman.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/soc/fsl/qbman/qman.c b/drivers/soc/fsl/qbman/qman.c
index 7dbcb475a59c..7f4c57999e08 100644
--- a/drivers/soc/fsl/qbman/qman.c
+++ b/drivers/soc/fsl/qbman/qman.c
@@ -850,12 +850,24 @@  static inline void qm_mr_set_ithresh(struct qm_portal *portal, u8 ithresh)
 
 static inline int qm_mc_init(struct qm_portal *portal)
 {
+	u8 rr0, rr1;
 	struct qm_mc *mc = &portal->mc;
 
 	mc->cr = portal->addr.ce + QM_CL_CR;
 	mc->rr = portal->addr.ce + QM_CL_RR0;
-	mc->rridx = (mc->cr->_ncw_verb & QM_MCC_VERB_VBIT)
-		    ? 0 : 1;
+	/*
+	 * The expected valid bit polarity for the next CR command is 0
+	 * if RR1 contains a valid response, and is 1 if RR0 contains a
+	 * valid response. If both RR contain all 0, this indicates either
+	 * that no command has been executed since reset (in which case the
+	 * expected valid bit polarity is 1)
+	 */
+	rr0 = mc->rr->verb;
+	rr1 = (mc->rr+1)->verb;
+	if ((rr0 == 0 && rr1 == 0) || rr0 != 0)
+		mc->rridx = 1;
+	else
+		mc->rridx = 0;
 	mc->vbit = mc->rridx ? QM_MCC_VERB_VBIT : 0;
 #ifdef CONFIG_FSL_DPAA_CHECKING
 	mc->state = qman_mc_idle;