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From: Kamal Dasu <kdasu.kdev@gmail.com>
To: broonie@kernel.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com,
	yendapally.reddy@broadcom.com, Kamal Dasu <kdasu.kdev@gmail.com>
Subject: [PATCH 2/2] spi: bcm-qspi: set transfer parameter only if they change
Date: Wed, 24 Nov 2021 14:33:53 -0500	[thread overview]
Message-ID: <20211124193353.32311-3-kdasu.kdev@gmail.com> (raw)
In-Reply-To: <20211124193353.32311-1-kdasu.kdev@gmail.com>

Check if the transfer parameters have changed from previous settings
before applying new parameters.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
 drivers/spi/spi-bcm-qspi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 38e6e2cb62ca..c9a769b8594b 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -598,12 +598,24 @@ static void bcm_qspi_chip_select(struct bcm_qspi *qspi, int cs)
 	qspi->curr_cs = cs;
 }
 
+static bool bcmspi_parms_did_change(const struct bcm_qspi_parms * const cur,
+				    const struct bcm_qspi_parms * const prev)
+{
+	return (cur->speed_hz != prev->speed_hz) ||
+		(cur->mode != prev->mode) ||
+		(cur->bits_per_word != prev->bits_per_word);
+}
+
+
 /* MSPI helpers */
 static void bcm_qspi_hw_set_parms(struct bcm_qspi *qspi,
 				  const struct bcm_qspi_parms *xp)
 {
 	u32 spcr, spbr = 0;
 
+	if (!bcmspi_parms_did_change(xp, &qspi->last_parms))
+		return;
+
 	if (!qspi->mspi_maj_rev)
 		/* legacy controller */
 		spcr = MSPI_MASTER_BIT;
-- 
2.17.1


  parent reply	other threads:[~2021-11-24 19:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-24 19:33 [PATCH 0/2] spi transfer paramater changes and baud rate calculation Kamal Dasu
2021-11-24 19:33 ` [PATCH 1/2] spi: bcm-qspi: choose sysclk setting based on requested speed Kamal Dasu
2021-11-24 19:33 ` Kamal Dasu [this message]
2021-11-25 13:37 ` [PATCH 0/2] spi transfer paramater changes and baud rate calculation Mark Brown

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