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SubjectRe: [PATCH 17/23] mtd: spi-nor: Fix clearing of QE bit on lock()/unlock()
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Hi Tudor

[...]

On 17-Sep-19 9:25 PM, Tudor.Ambarus@microchip.com wrote:
> +static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 status_new,
> + u8 mask)
> +{
> + int ret;
> + u8 *sr_cr = nor->bouncebuf;
> + u8 cr_written;
> +
> + /* Make sure we don't overwrite the contents of Status Register 2. */
> + if (!(nor->flags & SNOR_F_NO_READ_CR)) {

Assuming SNOR_F_NO_READ_CR is not set...

> + ret = spi_nor_read_cr(nor, &sr_cr[1]);
> + if (ret)
> + return ret;
> + } else if (nor->flash.quad_enable) {
> + /*
> + * If the Status Register 2 Read command (35h) is not
> + * supported, we should at least be sure we don't
> + * change the value of the SR2 Quad Enable bit.
> + *
> + * We can safely assume that when the Quad Enable method is
> + * set, the value of the QE bit is one, as a consequence of the
> + * nor->flash.quad_enable() call.
> + *
> + * We can safely assume that the Quad Enable bit is present in
> + * the Status Register 2 at BIT(1). According to the JESD216
> + * revB standard, BFPT DWORDS[15], bits 22:20, the 16-bit
> + * Write Status (01h) command is available just for the cases
> + * in which the QE bit is described in SR2 at BIT(1).
> + */
> + sr_cr[1] = CR_QUAD_EN_SPAN;
> + } else {
> + sr_cr[1] = 0;
> + }
> +

CR_QUAD_EN_SPAN will not be in sr_cr[1] when we reach here. So code
won't enable quad mode.


> + sr_cr[0] = status_new;
> +
> + ret = spi_nor_write_sr(nor, sr_cr, 2);
> + if (ret)
> + return ret;
> +
> + cr_written = sr_cr[1];
> +
> + ret = spi_nor_read_sr(nor, &sr_cr[0]);
> + if (ret)
> + return ret;
> +
> + if ((sr_cr[0] & mask) != (status_new & mask)) {
> + dev_err(nor->dev, "Read back test failed\n");
> + return -EIO;
> + }
> +
> + if (nor->flags & SNOR_F_NO_READ_CR)
> + return 0;
> +
> + ret = spi_nor_read_cr(nor, &sr_cr[1]);
> + if (ret)
> + return ret;
> +
> + if (cr_written != sr_cr[1]) {
> + dev_err(nor->dev, "Read back test failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +

Regards
Vignesh

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