Hi Miquel, On Tue, 3 Jul 2018 23:59:58 +0200 Miquel Raynal <[email protected]> wrote:
> In order to remove the limitation that forbids dynamic allocation in > nand_scan_ident(), we must create a path that will be the same for all > controller drivers. The idea is to use nand_scan() instead of the widely > implemented nand_scan_ident()/nand_scan_tail() couple. In order to > achieve this, controller drivers will need to adjust some parameters > between these two functions depending on the NAND chip wired on them. > > For that, a hook called ->attach_chip() is created in the > nand_hw_control structure. This structure may be referenced by two ways: > 1/ if the driver does not implement its own controller, the > chip->controller hook is not populated before nand_scan() so it > cannot be dereferenced: use chip->hwcontrol instead (which is > statically allocated and will be referenced later by chip->controller > anyway). > 2/ through chip->controller if the driver implements its own controller. > > Another hook, ->detach_chip() is also introduced in order to clean the > controller driver's potential allocations in case of failure of > nand_scan_tail(). There is no need for the controller driver to call the > ->detach_chip() hook directly upon error after a successful nand_scan(). > In this situation, calling nand_release() as before is enough. > > Signed-off-by: Miquel Raynal <[email protected]> > --- > drivers/mtd/nand/raw/nand_base.c | 21 +++++++++++++++++++-- > include/linux/mtd/rawnand.h | 6 ++++++ > 2 files changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/raw/nand_base.c > b/drivers/mtd/nand/raw/nand_base.c > index faac82b1e058..97a74d48b0cf 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -6712,11 +6712,23 @@ EXPORT_SYMBOL(nand_scan_tail); > int nand_scan_with_ids(struct mtd_info *mtd, int maxchips, > struct nand_flash_dev *ids) > { > + struct nand_chip *chip = mtd_to_nand(mtd); > int ret; > > ret = nand_scan_ident(mtd, maxchips, ids); > - if (!ret) > - ret = nand_scan_tail(mtd); > + if (ret) > + return ret; > + > + if (chip->controller->attach_chip) { > + ret = chip->controller->attach_chip(chip); > + if (ret) > + return ret; > + } > + > + ret = nand_scan_tail(mtd); > + if (ret && chip->controller->detach_chip) > + chip->controller->detach_chip(chip); > + > return ret; > } > EXPORT_SYMBOL(nand_scan_with_ids); > @@ -6744,7 +6756,12 @@ void nand_cleanup(struct nand_chip *chip) > > /* Free manufacturer priv data. */ > nand_manufacturer_cleanup(chip); > + > + /* Free controller specific allocations after chip identification */ > + if (chip->controller->detach_chip) > + chip->controller->detach_chip(chip); > } > + > EXPORT_SYMBOL_GPL(nand_cleanup); > > /** > diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h > index 0c6fb316b409..81654211e520 100644 > --- a/include/linux/mtd/rawnand.h > +++ b/include/linux/mtd/rawnand.h > @@ -517,11 +517,17 @@ struct nand_id { > * @wq: wait queue to sleep on if a NAND operation is in > * progress used instead of the per chip wait queue > * when a hw controller is available. > + * @attach_chip: Callback that may be called between nand_detect() and > + * nand_scan_tail() during nand_scan() (optional). > + * @detach_chip: Callback that may be called if nand_scan_tail() fails > + * (optional). > */ > struct nand_hw_control { > spinlock_t lock; > struct nand_chip *active; > wait_queue_head_t wq; > + int (*attach_chip)(struct nand_chip *chip); > + void (*detach_chip)(struct nand_chip *chip); > }; Can we instead declare a nand_controller_ops struct and then have nand_hw_control point to it. Something like: struct nand_controller_ops { int (*attach_chip)(struct nand_chip *chip); void (*detach_chip)(struct nand_chip *chip); }; struct nand_hw_control { ... const struct nand_controller_ops *ops; }; > > static inline void nand_hw_control_init(struct nand_hw_control *nfc) Regards, Boris
