From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Mark Brown <broonie@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
linux-spi@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] spi: rspi: Do not set SPCR_SPE in qspi_set_config_register()
Date: Thu, 7 Dec 2017 11:09:21 +0100 [thread overview]
Message-ID: <1512641361-4128-1-git-send-email-geert+renesas@glider.be> (raw)
The R-Car Gen2 Hardware User Manual Rev. 2.00 states:
If the master/slave mode select bit (MSTR) is modified while the SPI
function enable bit (SPE) is set to 1 (that is, this module is
enabled), the subsequent operation cannot be guaranteed.
Hence do not set SPCR_SPE when setting SPCR_MSTR, just like the
.set_config_register() implementations for other RSPI variants do.
Note that when booted from QSPI, the boot loader will have set SPCR_MSTR
already, hence usually the bit is never modified by the Linux driver.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/spi/spi-rspi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index c96eab723fd3fdb7..8ef05c9568ced5d7 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -377,8 +377,8 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
/* Sets SPCMD */
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
- /* Enables SPI function in master mode */
- rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
+ /* Sets RSPI mode */
+ rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
return 0;
}
--
2.7.4
next reply other threads:[~2017-12-07 10:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-07 10:09 Geert Uytterhoeven [this message]
2017-12-07 12:35 ` Applied "spi: rspi: Do not set SPCR_SPE in qspi_set_config_register()" to the spi tree Mark Brown
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