linux-kernel - [PATCH V2 2/5] mmc: mmci: avoid fake busy polling in mmci

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Date:   Fri, 26 Apr 2019 09:46:35 +0200
From:   Ludovic Barre <ludovic.Barre@...com>
To:     Ulf Hansson <ulf.hansson@...aro.org>,
        Rob Herring <robh+dt@...nel.org>
CC:     <srinivas.kandagatla@...aro.org>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-mmc@...r.kernel.org>,
        <linux-stm32@...md-mailman.stormreply.com>,
        Ludovic Barre <ludovic.barre@...com>
Subject: [PATCH V2 2/5] mmc: mmci: avoid fake busy polling in mmci_irq

From: Ludovic Barre <ludovic.barre@...com>

mmci_irq function loops until the status is totally cleared.
However the busy_detect_flag could occurred even if no busy
response is expected and that busy d0 line is low (like in
cmd11: voltage switch).
Like busy_detect_flag is handled into mmci_cmd_irq this flag
can be always excluded.

Signed-off-by: Ludovic Barre <ludovic.barre@...com>
---
 drivers/mmc/host/mmci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 049f8e3..a040f54 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1535,9 +1535,10 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
 		}
 
 		/*
-		 * Don't poll for busy completion in irq context.
+		 * Busy_detect_flag has been handled by mmci_cmd_irq,
+		 * it can be excluded to avoid to poll on it
 		 */
-		if (host->variant->busy_detect && host->busy_status)
+		if (host->variant->busy_detect_flag)
 			status &= ~host->variant->busy_detect_flag;
 
 		ret = 1;
-- 
2.7.4