From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Mark Brown <broonie@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>,
linux-spi@vger.kernel.org, Chen-Yu Tsai <wens@csie.org>,
Marc Kleine-Budde <mkl@pengutronix.de>,
kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 10/10] spi: spi-sun6i: sun6i_spi_transfer_one(): enable RF_RDY interrupt only if needed
Date: Mon, 6 Jul 2020 16:34:43 +0200 [thread overview]
Message-ID: <20200706143443.9855-11-mkl@pengutronix.de> (raw)
In-Reply-To: <20200706143443.9855-1-mkl@pengutronix.de>
In sun6i_spi_transfer_one() the RX FIFO Ready (SUN6I_INT_CTL_RF_RDY) is
unconditionally enabled.
A RX interrupt is only needed, if more data than fits into the FIFO is going to
be received during this transfer. As the RX-FIFO is drained during transfer
complete interrupt, enable the RX FIFO Ready interrupt only if the data doesn't
fit into the FIFO.
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
drivers/spi/spi-sun6i.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index bba9843c40c5..19238e1b76b4 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -190,7 +190,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
unsigned int start, end, tx_time;
unsigned int trig_level;
- unsigned int tx_len = 0;
+ unsigned int tx_len = 0, rx_len = 0;
int ret = 0;
u32 reg;
@@ -245,10 +245,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
* If it's a TX only transfer, we don't want to fill the RX
* FIFO with bogus data
*/
- if (sspi->rx_buf)
+ if (sspi->rx_buf) {
reg &= ~SUN6I_TFR_CTL_DHB;
- else
+ rx_len = tfr->len;
+ } else {
reg |= SUN6I_TFR_CTL_DHB;
+ }
/* We want to control the chip select manually */
reg |= SUN6I_TFR_CTL_CS_MANUAL;
@@ -302,8 +304,10 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
sun6i_spi_fill_fifo(sspi);
/* Enable the interrupts */
- reg = SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_RDY;
+ reg = SUN6I_INT_CTL_TC;
+ if (rx_len > sspi->fifo_depth)
+ reg |= SUN6I_INT_CTL_RF_RDY;
if (tx_len > sspi->fifo_depth)
reg |= SUN6I_INT_CTL_TF_ERQ;
--
2.27.0
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next prev parent reply other threads:[~2020-07-06 14:36 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 14:34 [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 01/10] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 02/10] spi: spi-sun6i: sun6i_spi_transfer_one(): report effectivly used speed_hz of transfer Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 03/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove useless goto Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 04/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove not needed masking of transfer length Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 05/10] spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET() Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 06/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 07/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): remove not needed length argument Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 08/10] spi: spi-sun6i: sun6i_spi_fill_fifo(): " Marc Kleine-Budde
2020-07-06 14:34 ` [PATCH v2 09/10] spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register Marc Kleine-Budde
2020-07-06 14:34 ` Marc Kleine-Budde [this message]
2020-07-06 15:40 ` [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements Mark Brown
2020-07-06 18:52 ` Mark Brown
2020-07-06 19:02 ` Mark Brown
2020-07-07 14:17 ` Mark Brown
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