Re: [PATCH v6 04/19] spi: spi-mem: allow specifying a command's extension

From: Pratyush Yadav
Date: Fri May 22 2020 - 14:23:35 EST


Hi Boris,

On 21/05/20 08:22PM, Boris Brezillon wrote:
> On Wed, 20 May 2020 22:00:38 +0530
> Pratyush Yadav <p.yadav@xxxxxx> wrote:
>
> As mentioned in one of my previous review, you should patch the mxic
> driver before extending the opcode field:
>
> --->8---
> diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
> index 69491f3a515d..c3f4136a7c1d 100644
> --- a/drivers/spi/spi-mxic.c
> +++ b/drivers/spi/spi-mxic.c
> @@ -356,6 +356,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
> int nio = 1, i, ret;
> u32 ss_ctrl;
> u8 addr[8];
> + u8 cmd[2];

Regarding your comment about bisect-ability, how about I change this to:

u8 cmd[sizeof(op->cmd.opcode)];

and put this patch before the change to 2-byte opcodes. This should also
make it resistent to further changes in opcode size. Does that sound
like a sane idea?

> ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
> if (ret)
> @@ -393,7 +394,10 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
> writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
> mxic->regs + HC_CFG);
>
> - ret = mxic_spi_data_xfer(mxic, &op->cmd.opcode, NULL, 1);
> + for (i = 0; i < op->cmd.nbytes; i++)
> + cmd[i] = op->cmd.opcode >> (8 * (op->cmd.nbytes - i - 1));
> +
> + ret = mxic_spi_data_xfer(mxic, cmd, NULL, op->cmd.nbytes);
> if (ret)
> goto out;
>

--
Regards,
Pratyush Yadav
Texas Instruments India