On Thu, 31 Jan 2019 16:15:28 +0000 <Tudor.Ambarus@xxxxxxxxxxxxx> wrote: > From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> > > Cache MR value to avoid write access when setting the controller > in Serial Memory Mode (SMM). SMM is set in exec_op() and not at > probe time, to let room for future regular SPI support. > > Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> > --- > v2: cache MR value instead of moving the write access at probe > > drivers/spi/atmel-quadspi.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c > index ddc712410812..fe05aee5d845 100644 > --- a/drivers/spi/atmel-quadspi.c > +++ b/drivers/spi/atmel-quadspi.c > @@ -155,6 +155,7 @@ struct atmel_qspi { > struct clk *clk; > struct platform_device *pdev; > u32 pending; > + u32 mr; > struct completion cmd_completion; > }; > > @@ -238,7 +239,9 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) > icr = QSPI_ICR_INST(op->cmd.opcode); > ifr = QSPI_IFR_INSTEN; > > - qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); > + /* Set the QSPI controller in Serial Memory Mode */ > + if (!(aq->mr & QSPI_MR_SMM)) if (aq->mr != QSPI_MR_SMM) > + qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); You need to update ->mr here. > > mode = find_mode(op); > if (mode < 0)