From: Pratyush Yadav <p.yadav@ti.com>
To: <patrice.chotard@foss.st.com>
Cc: Mark Brown <broonie@kernel.org>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Boris Brezillon <boris.brezillon@collabora.com>,
<linux-mtd@lists.infradead.org>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
<linux-spi@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <christophe.kerello@foss.st.com>
Subject: Re: mtd: spinand: add spi nand mtd resume handler
Date: Thu, 27 May 2021 15:30:17 +0530 [thread overview]
Message-ID: <20210527100015.abxcroi23zyvcyzk@ti.com> (raw)
In-Reply-To: <20210526153016.32653-1-patrice.chotard@foss.st.com>
On 26/05/21 05:30PM, patrice.chotard@foss.st.com wrote:
> From: Christophe Kerello <christophe.kerello@foss.st.com>
>
> After power up, all SPI NAND's blocks are locked. Only read operations
> are allowed, write and erase operations are forbidden.
> The SPI NAND framework unlocks all the blocks during its initialization.
>
> During a standby low power, the memory is powered down, losing its
> configuration.
> During the resume, the QSPI driver state is restored but the SPI NAND
> framework does not reconfigured the memory.
>
> This patch adds spi nand mtd PM handlers for resume ops.
> SPI NAND resume op re-initializes SPI NAND flash to its probed state.
>
> Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
> ---
> drivers/mtd/nand/spi/core.c | 56 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
>
> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> index 17f63f95f4a2..6abaf874eb3f 100644
> --- a/drivers/mtd/nand/spi/core.c
> +++ b/drivers/mtd/nand/spi/core.c
> @@ -1074,6 +1074,61 @@ static int spinand_detect(struct spinand_device *spinand)
> return 0;
> }
>
> +static void spinand_mtd_resume(struct mtd_info *mtd)
> +{
> + struct spinand_device *spinand = mtd_to_spinand(mtd);
> + struct nand_device *nand = mtd_to_nanddev(mtd);
> + struct device *dev = &spinand->spimem->spi->dev;
> + int ret, i;
> +
> + ret = spinand_reset_op(spinand);
> + if (ret)
> + return;
> +
> + ret = spinand_init_quad_enable(spinand);
> + if (ret) {
> + dev_err(dev,
> + "Failed to initialize the quad part (err = %d)\n",
> + ret);
> + return;
> + }
> +
> + ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
> + if (ret) {
> + dev_err(dev,
> + "Failed to updtae the OTP (err = %d)\n",
> + ret);
> + return;
> + }
Since you have reset the flash, this cache is invalid. You should reset
the cache and re-populate it before using it in any way.
> +
> + ret = spinand_manufacturer_init(spinand);
> + if (ret) {
> + dev_err(dev,
> + "Failed to initialize the SPI NAND chip (err = %d)\n",
> + ret);
> + return;
> + }
> +
> + /* After power up, all blocks are locked, so unlock them here. */
> + for (i = 0; i < nand->memorg.ntargets; i++) {
> + ret = spinand_select_target(spinand, i);
> + if (ret) {
> + dev_err(dev,
> + "Failed to select the target (err = %d)\n",
> + ret);
> + return;
> + }
> +
> + ret = spinand_lock_block(spinand, BL_ALL_UNLOCKED);
> + if (ret) {
> + dev_err(dev,
> + "Failed to unlock block (err = %d)\n",
> + ret);
> + return;
> + }
> + }
> +}
> +
Most of these seem to be copied from spinand_init(). I think it is
better to create a common function that can be called from both
spinand_init() and spinand_mtd_resume(). This way when someone adds
something new to the init procedure, like support for some other modes,
they won't have to remember to update it in two places.
> static int spinand_init(struct spinand_device *spinand)
> {
> struct device *dev = &spinand->spimem->spi->dev;
> @@ -1167,6 +1222,7 @@ static int spinand_init(struct spinand_device *spinand)
> mtd->_block_isreserved = spinand_mtd_block_isreserved;
> mtd->_erase = spinand_mtd_erase;
> mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
> + mtd->_resume = spinand_mtd_resume;
Is it possible that the userspace can use this mtd device before the
resume is finished? Is there a way to temporarily "pause" or unregister
an mtd device?
>
> if (nand->ecc.engine) {
> ret = mtd_ooblayout_count_freebytes(mtd);
--
Regards,
Pratyush Yadav
Texas Instruments Inc.
next prev parent reply other threads:[~2021-05-27 10:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 15:30 mtd: spinand: add spi nand mtd resume handler patrice.chotard
2021-05-26 15:42 ` Miquel Raynal
2021-05-27 7:01 ` Patrice CHOTARD
2021-05-27 7:32 ` [Linux-stm32] " Patrice CHOTARD
2021-05-27 10:00 ` Pratyush Yadav [this message]
2021-05-27 10:04 ` Miquel Raynal
2021-05-27 13:50 ` Patrice CHOTARD
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