| Message ID | 20200216172117.49832-7-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Regmap over USB for Multifunction USB Device (gpio, display, ...) | expand |
On Sun, Feb 16, 2020 at 06:21:14PM +0100, Noralf Trønnes wrote: > When writing a 3MB buffer the unwritable check in _regmap_raw_write_impl() > adds a ~20ms overhead on a Raspberry Pi 4. > Amend this by avoiding the check if it's not necessary. This is a generic optimization, why is it mixed in with the rest of this series? There is no dependency either way :( > /* Check for unwritable registers before we start */ > - for (i = 0; i < val_len / map->format.val_bytes; i++) > - if (!regmap_writeable(map, > - reg + regmap_get_offset(map, i))) > - return -EINVAL; > + if (map->max_register || map->writeable_reg || map->wr_table) { > + for (i = 0; i < val_len / map->format.val_bytes; i++) > + if (!regmap_writeable(map, > + reg + regmap_get_offset(map, i))) > + return -EINVAL; > + } This is going to break if there is any change to the implementation of regmap_writeable(). The code should at least be next to that if not actually shared so that this doesn't happen. I'd suggest implementing a function regmap_writeable_range() and then making regmap_writeable() call that.
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 19f57ccfbe1d..cd876309a74b 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1489,10 +1489,12 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg, WARN_ON(!map->bus); /* Check for unwritable registers before we start */ - for (i = 0; i < val_len / map->format.val_bytes; i++) - if (!regmap_writeable(map, - reg + regmap_get_offset(map, i))) - return -EINVAL; + if (map->max_register || map->writeable_reg || map->wr_table) { + for (i = 0; i < val_len / map->format.val_bytes; i++) + if (!regmap_writeable(map, + reg + regmap_get_offset(map, i))) + return -EINVAL; + } if (!map->cache_bypass && map->format.parse_val) { unsigned int ival;
When writing a 3MB buffer the unwritable check in _regmap_raw_write_impl() adds a ~20ms overhead on a Raspberry Pi 4. Amend this by avoiding the check if it's not necessary. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> --- drivers/base/regmap/regmap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)