| Submitter | Dmitry Eremin-Solenikov |
|---|---|
| Date | June 7, 2011, 3:48 p.m. |
| Message ID | <1307461738-16811-1-git-send-email-dbaryshkov@gmail.com> |
| Download | mbox | patch |
| Permalink | /patch/99276/ |
| State | New |
| Headers | show |
Comments
I agree we need a good comment, but I find this one difficult to follow. On Tue, 2011-06-07 at 19:48 +0400, Dmitry Eremin-Solenikov wrote: > /** > + * mtd_device_parse_register - register an MTD device. Not just register, it also contains parsing functionality. > + * > + * @mtd: the MTD device to register > + * @part_probe_types: the list of MTD partition probes to try Please, name it 'types' to be consistent with 'parse_mtd_partitions()'. Also, you do not say that this can be %NULL. With my patch, you can refer the reader like "see 'parse_mtd_partitions()' for more information'. > + * @origin: start address of MTD device. =0 unless you are sure you need this. Try to avoid using dots. Also, constants should be prefixed with %, i.e., use %0. > + * @defparts: default partition information to register. Only valid if > + * defnr_parts > 0 Ditto about a dot, prefix variables with @, i.e., in this case: @defnr_parts > %0. Also about naming: why "default"? What is default there? This is more like "alternative, or fall-back" - you first try to detect partition specified in @part_probe_types, if if you fail - you use "alternative" partitions. Please, rename it. > + * @defnr_parts: the number of partitions in defparts. If zero then the full > + * MTD device is registered if no partition info is found Ditto. > + * > + * Extract partition info and register MTD device (partitions or a whole device) > + * It calls parse_mtd_partitions(), checks the result. If there were no > + * partitions found, it uses default info specified (via defparts/defnr_parts) > + * and then registers either partitions, or (if no partitions were > + * found/specified) the whow MTD. > + */ Sorry, I find this unreadable. I suggest something like this. This function aggregates MTD partitions parsing (done by 'parse_mtd_partitions()') and MTD device and partitions registering. It basically follows the most common pattern found in many MTD drivers: o It first tries to probe partitions on MTD device @mtd using parsers specified in @types (if @types is %NULL, then the default list of parsers is used, see 'parse_mtd_partitions()' for more information). o If this succeeds, this function registers the found partitions, as well as the whole MTD device @mtd. o If no partitions were found this function just registers the MTD device @mtd and exits. Returns zero in case of success and a negative error code in case of failure. Would you please amend the patch and re-send?
On Tue, Jun 07, 2011 at 07:48:58PM +0400, Dmitry Eremin-Solenikov wrote: > Lots (nearly all) mtd drivers contain nearly the similar code that > calls parse_mtd_partitions, provides some platform-default values, if > parsing fails, and registers mtd device. > > This is an aim to provide single implementation of this scenario: > mtd_device_parse_register() which will handle all this parsing and > defaults. > > Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> > --- > drivers/mtd/mtdcore.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/mtd/mtd.h | 5 +++++ > 2 files changed, 52 insertions(+), 0 deletions(-) > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c > index c510aff..d538e0a 100644 > --- a/drivers/mtd/mtdcore.c > +++ b/drivers/mtd/mtdcore.c > @@ -452,6 +452,53 @@ int mtd_device_register(struct mtd_info *master, > EXPORT_SYMBOL_GPL(mtd_device_register); > > /** > + * mtd_device_parse_register - register an MTD device. > + * > + * @mtd: the MTD device to register > + * @part_probe_types: the list of MTD partition probes to try > + * @origin: start address of MTD device. =0 unless you are sure you need this. > + * @defparts: default partition information to register. Only valid if > + * defnr_parts > 0 > + * @defnr_parts: the number of partitions in defparts. If zero then the full > + * MTD device is registered if no partition info is found > + * > + * Extract partition info and register MTD device (partitions or a whole device) > + * It calls parse_mtd_partitions(), checks the result. If there were no > + * partitions found, it uses default info specified (via defparts/defnr_parts) > + * and then registers either partitions, or (if no partitions were > + * found/specified) the whow MTD. s/whow/whole ? > + */ > +int mtd_device_parse_register(struct mtd_info *mtd, > + const char **part_probe_types, > + unsigned long origin, > + const struct mtd_partition *defparts, > + int defnr_parts) > +{ > + int err; > + struct mtd_partition *parts; > + > + err = parse_mtd_partitions(mtd, part_probe_types, &parts, origin); > + if (err <= 0 && defnr_parts) { > + parts = kmemdup(defparts, sizeof(*parts) * defnr_parts, > + GFP_KERNEL); > + if (!parts) > + err = -ENOMEM; > + } I see that some of your patches for drivers (e.g. plat_nand) remove the kfree() of the partitions but this doesn't appear to be handled anywhere else afaict. I don't think this can be done in mtd_device_unregister() as it doesn't have the mtd_partition array so probably needs to remain in the driver. Jamie
On 6/8/11, Jamie Iles <jamie@jamieiles.com> wrote: > On Tue, Jun 07, 2011 at 07:48:58PM +0400, Dmitry Eremin-Solenikov wrote: >> Lots (nearly all) mtd drivers contain nearly the similar code that >> calls parse_mtd_partitions, provides some platform-default values, if >> parsing fails, and registers mtd device. >> >> This is an aim to provide single implementation of this scenario: >> mtd_device_parse_register() which will handle all this parsing and >> defaults. >> >> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> >> --- >> drivers/mtd/mtdcore.c | 47 >> +++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/mtd/mtd.h | 5 +++++ >> 2 files changed, 52 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c >> index c510aff..d538e0a 100644 >> --- a/drivers/mtd/mtdcore.c >> +++ b/drivers/mtd/mtdcore.c >> @@ -452,6 +452,53 @@ int mtd_device_register(struct mtd_info *master, >> EXPORT_SYMBOL_GPL(mtd_device_register); >> >> /** >> + * mtd_device_parse_register - register an MTD device. >> + * >> + * @mtd: the MTD device to register >> + * @part_probe_types: the list of MTD partition probes to try >> + * @origin: start address of MTD device. =0 unless you are sure you need >> this. >> + * @defparts: default partition information to register. Only valid if >> + * defnr_parts > 0 >> + * @defnr_parts: the number of partitions in defparts. If zero then the >> full >> + * MTD device is registered if no partition info is found >> + * >> + * Extract partition info and register MTD device (partitions or a whole >> device) >> + * It calls parse_mtd_partitions(), checks the result. If there were no >> + * partitions found, it uses default info specified (via >> defparts/defnr_parts) >> + * and then registers either partitions, or (if no partitions were >> + * found/specified) the whow MTD. > > s/whow/whole ? Yup. >> + */ >> +int mtd_device_parse_register(struct mtd_info *mtd, >> + const char **part_probe_types, >> + unsigned long origin, >> + const struct mtd_partition *defparts, >> + int defnr_parts) >> +{ >> + int err; >> + struct mtd_partition *parts; >> + >> + err = parse_mtd_partitions(mtd, part_probe_types, &parts, origin); >> + if (err <= 0 && defnr_parts) { >> + parts = kmemdup(defparts, sizeof(*parts) * defnr_parts, >> + GFP_KERNEL); >> + if (!parts) >> + err = -ENOMEM; >> + } > > I see that some of your patches for drivers (e.g. plat_nand) remove the > kfree() of the partitions but this doesn't appear to be handled anywhere > else afaict. I don't think this can be done in mtd_device_unregister() > as it doesn't have the mtd_partition array so probably needs to remain > in the driver. It's handled by kfree right aftert add_mtd_partitions. No mtd partitions information is exported out of mtd_device_parse_register(). In fact I'll have to check if I can remove all <mtd/partitions.h> includes from drivers. Anyway I'll post a V2 later after fixing issues identified by you and Artem.
Patch
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index c510aff..d538e0a 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -452,6 +452,53 @@ int mtd_device_register(struct mtd_info *master, EXPORT_SYMBOL_GPL(mtd_device_register); /** + * mtd_device_parse_register - register an MTD device. + * + * @mtd: the MTD device to register + * @part_probe_types: the list of MTD partition probes to try + * @origin: start address of MTD device. =0 unless you are sure you need this. + * @defparts: default partition information to register. Only valid if + * defnr_parts > 0 + * @defnr_parts: the number of partitions in defparts. If zero then the full + * MTD device is registered if no partition info is found + * + * Extract partition info and register MTD device (partitions or a whole device) + * It calls parse_mtd_partitions(), checks the result. If there were no + * partitions found, it uses default info specified (via defparts/defnr_parts) + * and then registers either partitions, or (if no partitions were + * found/specified) the whow MTD. + */ +int mtd_device_parse_register(struct mtd_info *mtd, + const char **part_probe_types, + unsigned long origin, + const struct mtd_partition *defparts, + int defnr_parts) +{ + int err; + struct mtd_partition *parts; + + err = parse_mtd_partitions(mtd, part_probe_types, &parts, origin); + if (err <= 0 && defnr_parts) { + parts = kmemdup(defparts, sizeof(*parts) * defnr_parts, + GFP_KERNEL); + if (!parts) + err = -ENOMEM; + } + + if (err > 0) { + err = add_mtd_partitions(mtd, parts, err); + kfree(parts); + } else if (err == 0) { + err = add_mtd_device(mtd); + if (err == 1) + err = -ENODEV; + } + + return err; +} +EXPORT_SYMBOL_GPL(mtd_device_parse_register); + +/** * mtd_device_unregister - unregister an existing MTD device. * * @master: the MTD device to unregister. This will unregister both the master diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 2541fb8..d28a241 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -327,6 +327,11 @@ struct mtd_partition; extern int mtd_device_register(struct mtd_info *master, const struct mtd_partition *parts, int nr_parts); +extern int mtd_device_parse_register(struct mtd_info *mtd, + const char **part_probe_types, + unsigned long origin, + const struct mtd_partition *defparts, + int defnr_parts); extern int mtd_device_unregister(struct mtd_info *master); extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num); extern int __get_mtd_device(struct mtd_info *mtd);
Lots (nearly all) mtd drivers contain nearly the similar code that calls parse_mtd_partitions, provides some platform-default values, if parsing fails, and registers mtd device. This is an aim to provide single implementation of this scenario: mtd_device_parse_register() which will handle all this parsing and defaults. Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> --- drivers/mtd/mtdcore.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/mtd.h | 5 +++++ 2 files changed, 52 insertions(+), 0 deletions(-)