[3/3] mtd: cfi_cmdset_{0001, 0002}: use common MTD reboot boilerplate
Guenter Roeck
linux at roeck-us.net
Mon Nov 2 14:16:33 PST 2015
On Mon, Nov 02, 2015 at 01:58:18PM -0800, Brian Norris wrote:
> On Mon, Nov 02, 2015 at 12:05:13PM -0800, Guenter Roeck wrote:
> > On Thu, Dec 04, 2014 at 06:36:08PM -0800, Brian Norris wrote:
> > > We don't have to implement this glue code in the chip driver any more.
> > >
> > > Signed-off-by: Brian Norris <computersforpeace at gmail.com>
> > > ---
> > > Not tested yet
> > >
> > Tested-by: Guenter Roeck <linux at roeck-us.net>
>
> Thanks! Did you verify that your reboot notifier callback (e.g.,
> cfi_intelext_reset()) is actually called on reboot?
>
No, I just verified that it boots and shuts down correctly.
Do you want me to verify if the notifier is called, given the
problems you discovered with the patch ?
Thanks,
Guenter
> And actually, I do see a problem with this patch now, so I'm less likely
> to take it as-is; we never guarantee that this mtd_info struct actually
> gets registered via mtd_device_parse_register(), so even though we
> stick the right callback in mtd->_reboot(), we haven't actually ensured
> it will ever get called.
>
> See, for instance, the calling path in (speaking of the devil)
> arch/cris/arch-v10/drivers/axisflashmap.c:
>
> static struct mtd_info *flash_probe(void)
> {
> ...
> mtd_cse0 = probe_cs(&map_cse0);
> mtd_cse1 = probe_cs(&map_cse1);
> ...
> if (mtd_cse0 && mtd_cse1) {
> struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
>
> ...
> mtd_cse = mtd_concat_create(mtds, ARRAY_SIZE(mtds),
> "cse0+cse1");
>
>
> So, either of map_cse0 or map_cse1 could be a CFI-based map, and so only the
> concatenation would be registered, and therefore the reboot() notifier will
> just be left assigned to the sub-device, but never registered with the core.
>
> Now, it looks like this is one of very few cases that we'd have to worry
> about... right now I've only found physmap_of.c that does the same
> mtdconcat stuff. So maybe if we fixed mtdconcat, we could solve this...
>
> MTD is too hairy :(
>
> Anyway, I'll have to NAK my own patch still, and we should probalby go
> with your other solution to your current problems from here:
>
> http://lists.infradead.org/pipermail/linux-mtd/2015-November/063022.html
>
> Regards,
> Brian
>
> > > drivers/mtd/chips/cfi_cmdset_0001.c | 22 +++-------------------
> > > drivers/mtd/chips/cfi_cmdset_0002.c | 22 +++-------------------
> > > 2 files changed, 6 insertions(+), 38 deletions(-)
> > >
> > > diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
> > > index 286b97a304cf..3df9744496b2 100644
> > > --- a/drivers/mtd/chips/cfi_cmdset_0001.c
> > > +++ b/drivers/mtd/chips/cfi_cmdset_0001.c
> > > @@ -28,7 +28,6 @@
> > > #include <linux/slab.h>
> > > #include <linux/delay.h>
> > > #include <linux/interrupt.h>
> > > -#include <linux/reboot.h>
> > > #include <linux/bitmap.h>
> > > #include <linux/mtd/xip.h>
> > > #include <linux/mtd/map.h>
> > > @@ -80,7 +79,7 @@ static int cfi_intelext_get_user_prot_info(struct mtd_info *, size_t,
> > > #endif
> > > static int cfi_intelext_suspend (struct mtd_info *);
> > > static void cfi_intelext_resume (struct mtd_info *);
> > > -static int cfi_intelext_reboot (struct notifier_block *, unsigned long, void *);
> > > +static void cfi_intelext_reset(struct mtd_info *);
> > >
> > > static void cfi_intelext_destroy(struct mtd_info *);
> > >
> > > @@ -486,13 +485,12 @@ struct mtd_info *cfi_cmdset_0001(struct map_info *map, int primary)
> > > mtd->_is_locked = cfi_intelext_is_locked;
> > > mtd->_suspend = cfi_intelext_suspend;
> > > mtd->_resume = cfi_intelext_resume;
> > > + mtd->_reboot = cfi_intelext_reset;
> > > mtd->flags = MTD_CAP_NORFLASH;
> > > mtd->name = map->name;
> > > mtd->writesize = 1;
> > > mtd->writebufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
> > >
> > > - mtd->reboot_notifier.notifier_call = cfi_intelext_reboot;
> > > -
> > > if (cfi->cfi_mode == CFI_MODE_CFI) {
> > > /*
> > > * It's a real CFI chip, not one for which the probe
> > > @@ -646,7 +644,6 @@ static struct mtd_info *cfi_intelext_setup(struct mtd_info *mtd)
> > > goto setup_err;
> > >
> > > __module_get(THIS_MODULE);
> > > - register_reboot_notifier(&mtd->reboot_notifier);
> > > return mtd;
> > >
> > > setup_err:
> > > @@ -2605,7 +2602,7 @@ static void cfi_intelext_resume(struct mtd_info *mtd)
> > > cfi_intelext_restore_locks(mtd);
> > > }
> > >
> > > -static int cfi_intelext_reset(struct mtd_info *mtd)
> > > +static void cfi_intelext_reset(struct mtd_info *mtd)
> > > {
> > > struct map_info *map = mtd->priv;
> > > struct cfi_private *cfi = map->fldrv_priv;
> > > @@ -2626,18 +2623,6 @@ static int cfi_intelext_reset(struct mtd_info *mtd)
> > > }
> > > mutex_unlock(&chip->mutex);
> > > }
> > > -
> > > - return 0;
> > > -}
> > > -
> > > -static int cfi_intelext_reboot(struct notifier_block *nb, unsigned long val,
> > > - void *v)
> > > -{
> > > - struct mtd_info *mtd;
> > > -
> > > - mtd = container_of(nb, struct mtd_info, reboot_notifier);
> > > - cfi_intelext_reset(mtd);
> > > - return NOTIFY_DONE;
> > > }
> > >
> > > static void cfi_intelext_destroy(struct mtd_info *mtd)
> > > @@ -2647,7 +2632,6 @@ static void cfi_intelext_destroy(struct mtd_info *mtd)
> > > struct mtd_erase_region_info *region;
> > > int i;
> > > cfi_intelext_reset(mtd);
> > > - unregister_reboot_notifier(&mtd->reboot_notifier);
> > > kfree(cfi->cmdset_priv);
> > > kfree(cfi->cfiq);
> > > kfree(cfi->chips[0].priv);
> > > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> > > index c50d8cf0f60d..c4f63482cf96 100644
> > > --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> > > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> > > @@ -31,7 +31,6 @@
> > > #include <linux/slab.h>
> > > #include <linux/delay.h>
> > > #include <linux/interrupt.h>
> > > -#include <linux/reboot.h>
> > > #include <linux/of.h>
> > > #include <linux/of_platform.h>
> > > #include <linux/mtd/map.h>
> > > @@ -57,7 +56,7 @@ static int cfi_amdstd_erase_varsize(struct mtd_info *, struct erase_info *);
> > > static void cfi_amdstd_sync (struct mtd_info *);
> > > static int cfi_amdstd_suspend (struct mtd_info *);
> > > static void cfi_amdstd_resume (struct mtd_info *);
> > > -static int cfi_amdstd_reboot(struct notifier_block *, unsigned long, void *);
> > > +static void cfi_amdstd_reset(struct mtd_info *);
> > > static int cfi_amdstd_get_fact_prot_info(struct mtd_info *, size_t,
> > > size_t *, struct otp_info *);
> > > static int cfi_amdstd_get_user_prot_info(struct mtd_info *, size_t,
> > > @@ -529,6 +528,7 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
> > > mtd->_sync = cfi_amdstd_sync;
> > > mtd->_suspend = cfi_amdstd_suspend;
> > > mtd->_resume = cfi_amdstd_resume;
> > > + mtd->_reboot = cfi_amdstd_reset;
> > > mtd->_read_user_prot_reg = cfi_amdstd_read_user_prot_reg;
> > > mtd->_read_fact_prot_reg = cfi_amdstd_read_fact_prot_reg;
> > > mtd->_get_fact_prot_info = cfi_amdstd_get_fact_prot_info;
> > > @@ -544,7 +544,6 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
> > > mtd->writebufsize);
> > >
> > > mtd->_panic_write = cfi_amdstd_panic_write;
> > > - mtd->reboot_notifier.notifier_call = cfi_amdstd_reboot;
> > >
> > > if (cfi->cfi_mode==CFI_MODE_CFI){
> > > unsigned char bootloc;
> > > @@ -717,7 +716,6 @@ static struct mtd_info *cfi_amdstd_setup(struct mtd_info *mtd)
> > > }
> > >
> > > __module_get(THIS_MODULE);
> > > - register_reboot_notifier(&mtd->reboot_notifier);
> > > return mtd;
> > >
> > > setup_err:
> > > @@ -2871,7 +2869,7 @@ static void cfi_amdstd_resume(struct mtd_info *mtd)
> > > * the flash is in query/program/erase mode will prevent the CPU from
> > > * fetching the bootloader code, requiring a hard reset or power cycle.
> > > */
> > > -static int cfi_amdstd_reset(struct mtd_info *mtd)
> > > +static void cfi_amdstd_reset(struct mtd_info *mtd)
> > > {
> > > struct map_info *map = mtd->priv;
> > > struct cfi_private *cfi = map->fldrv_priv;
> > > @@ -2893,19 +2891,6 @@ static int cfi_amdstd_reset(struct mtd_info *mtd)
> > >
> > > mutex_unlock(&chip->mutex);
> > > }
> > > -
> > > - return 0;
> > > -}
> > > -
> > > -
> > > -static int cfi_amdstd_reboot(struct notifier_block *nb, unsigned long val,
> > > - void *v)
> > > -{
> > > - struct mtd_info *mtd;
> > > -
> > > - mtd = container_of(nb, struct mtd_info, reboot_notifier);
> > > - cfi_amdstd_reset(mtd);
> > > - return NOTIFY_DONE;
> > > }
> > >
> > >
> > > @@ -2915,7 +2900,6 @@ static void cfi_amdstd_destroy(struct mtd_info *mtd)
> > > struct cfi_private *cfi = map->fldrv_priv;
> > >
> > > cfi_amdstd_reset(mtd);
> > > - unregister_reboot_notifier(&mtd->reboot_notifier);
> > > kfree(cfi->cmdset_priv);
> > > kfree(cfi->cfiq);
> > > kfree(cfi);
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