This is a note to let you know that I've just added the patch titled
spi: omap2-mcspi: Configure hardware when slave driver changes mode
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-omap2-mcspi-configure-hardware-when-slave-driver-changes-mode.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 97ca0d6cc118716840ea443e010cb3d5f2d25eaf Mon Sep 17 00:00:00 2001
From: "Mark A. Greer" <mgreer@xxxxxxxxxxxxxxx>
Date: Tue, 1 Jul 2014 20:28:32 -0700
Subject: spi: omap2-mcspi: Configure hardware when slave driver changes mode
From: "Mark A. Greer" <mgreer@xxxxxxxxxxxxxxx>
commit 97ca0d6cc118716840ea443e010cb3d5f2d25eaf upstream.
Commit id 2bd16e3e23d9df41592c6b257c59b6860a9cc3ea
(spi: omap2-mcspi: Do not configure the controller
on each transfer unless needed) does its job too
well so omap2_mcspi_setup_transfer() isn't called
even when an SPI slave driver changes 'spi->mode'.
The result is that the mode requested by the SPI
slave driver never takes effect.
Fix this by adding the 'mode' member to the
omap2_mcspi_cs structure which holds the mode
value that the hardware is configured for.
When the SPI slave driver changes 'spi->mode'
it will be different than the value of this new
member and the SPI master driver will know that
the hardware must be reconfigured (by calling
omap2_mcspi_setup_transfer()).
Fixes: 2bd16e3e23 (spi: omap2-mcspi: Do not configure the controller on each transfer unless needed)
Signed-off-by: Mark A. Greer <mgreer@xxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -136,6 +136,7 @@ struct omap2_mcspi_cs {
void __iomem *base;
unsigned long phys;
int word_len;
+ u16 mode;
struct list_head node;
/* Context save and restore shadow register */
u32 chconf0;
@@ -801,6 +802,8 @@ static int omap2_mcspi_setup_transfer(st
mcspi_write_chconf0(spi, l);
+ cs->mode = spi->mode;
+
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
OMAP2_MCSPI_MAX_FREQ >> div,
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
@@ -871,6 +874,7 @@ static int omap2_mcspi_setup(struct spi_
return -ENOMEM;
cs->base = mcspi->base + spi->chip_select * 0x14;
cs->phys = mcspi->phys + spi->chip_select * 0x14;
+ cs->mode = 0;
cs->chconf0 = 0;
spi->controller_state = cs;
/* Link this to context save list */
@@ -1043,6 +1047,16 @@ static void omap2_mcspi_work(struct omap
mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
}
+ /*
+ * The slave driver could have changed spi->mode in which case
+ * it will be different from cs->mode (the current hardware setup).
+ * If so, set par_override (even though its not a parity issue) so
+ * omap2_mcspi_setup_transfer will be called to configure the hardware
+ * with the correct mode on the first iteration of the loop below.
+ */
+ if (spi->mode != cs->mode)
+ par_override = 1;
+
omap2_mcspi_set_enable(spi, 0);
m->status = status;
Patches currently in stable-queue which might be from mgreer@xxxxxxxxxxxxxxx are
queue-3.10/spi-omap2-mcspi-configure-hardware-when-slave-driver-changes-mode.patch
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