Unverified Commit b458a349 authored Dec 07, 2017 by Geert Uytterhoeven Committed by Mark Brown Dec 07, 2017

spi: rspi: Do not set SPCR_SPE in qspi_set_config_register()



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>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 4fbd8d19

drivers/spi/spi-rspi.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

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