Messages in this thread | | | Subject | Re: [PATCH] mtd: rawnand: check nand support for cache reads | From | Rouven Czerwinski <> | Date | Fri, 22 Sep 2023 12:07:42 +0200 |
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On Fri, 2023-09-22 at 12:04 +0200, Martin Hundebøll wrote: > On Fri, 2023-09-22 at 12:01 +0200, Rouven Czerwinski wrote: > > Both the JEDEC and ONFI specification say that read cache > > sequential > > support is an optional command. This means that we not only need to > > check whether the individual controller implements the command, we > > also > > need to check the parameter pages for both ONFI and JEDEC NAND > > flashes > > before enabling sequential cache reads. > > > > This fixes support for NAND flashes which don't support enabling > > cache > > reads, i.e. Samsung K9F4G08U0F or Toshiba TC58NVG0S3HTA00. > > > > Sequential cache reads are no only available for ONFI and JEDEC > > devices, > > if individual vendors implement this, it needs to be enabled per > > vendor. > > > > Tested on i.MX6Q with a Samsung NAND flash chip that doesn't > > support > > sequential reads. > > > > Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache > > reads") > > > > Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de> > > --- > > @Martin, Måns: > > I would appreciate if you could test this on your hardware. > > > > @Miguel: > > I didn't have the time to test this on ONFI/JEDEC devices with > > support > > yet, I'd be fine if you hold off merging this. > > > > drivers/mtd/nand/raw/nand_base.c | 3 +++ > > drivers/mtd/nand/raw/nand_jedec.c | 3 +++ > > drivers/mtd/nand/raw/nand_onfi.c | 3 +++ > > include/linux/mtd/jedec.h | 3 +++ > > include/linux/mtd/onfi.h | 1 + > > include/linux/mtd/rawnand.h | 1 + > > 6 files changed, 14 insertions(+) > > > > diff --git a/drivers/mtd/nand/raw/nand_base.c > > b/drivers/mtd/nand/raw/nand_base.c > > index d4b55155aeae..1fcac403cee6 100644 > > --- a/drivers/mtd/nand/raw/nand_base.c > > +++ b/drivers/mtd/nand/raw/nand_base.c > > @@ -5110,6 +5110,9 @@ static void > > rawnand_check_cont_read_support(struct nand_chip *chip) > > { > > struct mtd_info *mtd = nand_to_mtd(chip); > > > > + if (!chip->parameters.supports_read_cache) > > + return; > > + > > if (chip->read_retries) > > return; > > > > diff --git a/drivers/mtd/nand/raw/nand_jedec.c > > b/drivers/mtd/nand/raw/nand_jedec.c > > index 836757717660..e6ecbc4b2493 100644 > > --- a/drivers/mtd/nand/raw/nand_jedec.c > > +++ b/drivers/mtd/nand/raw/nand_jedec.c > > @@ -94,6 +94,9 @@ int nand_jedec_detect(struct nand_chip *chip) > > goto free_jedec_param_page; > > } > > > > + if (p->opt_cmd[0] & JEDEC_OPT_CMD_READ_CACHE) > > + chip->parameters.supports_read_cache; > > Missing ` = true` here ? > > > + > > memorg->pagesize = le32_to_cpu(p->byte_per_page); > > mtd->writesize = memorg->pagesize; > > > > diff --git a/drivers/mtd/nand/raw/nand_onfi.c > > b/drivers/mtd/nand/raw/nand_onfi.c > > index f15ef90aec8c..bf79bf2b5866 100644 > > --- a/drivers/mtd/nand/raw/nand_onfi.c > > +++ b/drivers/mtd/nand/raw/nand_onfi.c > > @@ -303,6 +303,9 @@ int nand_onfi_detect(struct nand_chip *chip) > > ONFI_FEATURE_ADDR_TIMING_MODE, 1); > > } > > > > + if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_READ_CACHE) > > + chip->parameters.supports_read_cache; > > And here? > > // Martin
Argh, totally. This should still fix your device, but cause performance regressions on devices supporting cached sequential reads. Unfortunately I don't have hardware to test this.
Fixed locally, I'll send a v2 later.
> > + > > onfi = kzalloc(sizeof(*onfi), GFP_KERNEL); > > if (!onfi) { > > ret = -ENOMEM; > > diff --git a/include/linux/mtd/jedec.h b/include/linux/mtd/jedec.h > > index 0b6b59f7cfbd..56047a4e54c9 100644 > > --- a/include/linux/mtd/jedec.h > > +++ b/include/linux/mtd/jedec.h > > @@ -21,6 +21,9 @@ struct jedec_ecc_info { > > /* JEDEC features */ > > #define JEDEC_FEATURE_16_BIT_BUS (1 << 0) > > > > +/* JEDEC Optional Commands */ > > +#define JEDEC_OPT_CMD_READ_CACHE BIT(1) > > + > > struct nand_jedec_params { > > /* rev info and features block */ > > /* 'J' 'E' 'S' 'D' */ > > diff --git a/include/linux/mtd/onfi.h b/include/linux/mtd/onfi.h > > index a7376f9beddf..55ab2e4d62f9 100644 > > --- a/include/linux/mtd/onfi.h > > +++ b/include/linux/mtd/onfi.h > > @@ -55,6 +55,7 @@ > > #define ONFI_SUBFEATURE_PARAM_LEN 4 > > > > /* ONFI optional commands SET/GET FEATURES supported? */ > > +#define ONFI_OPT_CMD_READ_CACHE BIT(1) > > #define ONFI_OPT_CMD_SET_GET_FEATURES BIT(2) > > > > struct nand_onfi_params { > > diff --git a/include/linux/mtd/rawnand.h > > b/include/linux/mtd/rawnand.h > > index 90a141ba2a5a..766856fcaba8 100644 > > --- a/include/linux/mtd/rawnand.h > > +++ b/include/linux/mtd/rawnand.h > > @@ -233,6 +233,7 @@ struct nand_parameters { > > /* Generic parameters */ > > const char *model; > > bool supports_set_get_features; > > + bool supports_read_cache; > > DECLARE_BITMAP(set_feature_list, ONFI_FEATURE_NUMBER); > > DECLARE_BITMAP(get_feature_list, ONFI_FEATURE_NUMBER); > > > >
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