_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.
To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.
At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This reverts commit bc8ce4 (regmap: don't corrupt work buffer in
_regmap_raw_write()) since it turns out that it can cause issues when
taken in isolation from the other changes in -next that lead to its
discovery. On the basis that nobody noticed the problems for quite some
time without that subsequent work let's drop it from v3.9.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Fix format specifier in dev_dbg and suppress the following warning
drivers/base/regmap/regcache.c: In function
‘regcache_sync_block_raw_flush’:
drivers/base/regmap/regcache.c:593:2: warning: format ‘%d’ expects
argument of type ‘int’, but argument 4 has type ‘size_t’ [-Wformat]
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
regcache_sync_block_raw is used only in this file. Hence make it static.
Silences the following warning:
drivers/base/regmap/regcache.c:608:5: warning:
symbol 'regcache_sync_block_raw' was not declared. Should it be static?
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
When syncing blocks of data using raw writes combine the writes into a
single block write, saving us bus overhead for setup, addressing and
teardown.
Currently the block write is done unconditionally as it is expected that
hardware which has a register format which can support raw writes will
support auto incrementing writes, this decision may need to be revised in
future.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
The idea of holding blocks of registers in device format is shared between
at least rbtree and lzo cache formats so split out the loop that does the
sync from the rbtree code so optimisations on it can be reused.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
The idea of maintaining a bitmap of present registers is something that
can usefully be used by other cache types that maintain blocks of cached
registers so move the code out of the rbtree cache and into the generic
regcache code.
Refactor the interface slightly as we go to wrap the set bit and enlarge
bitmap operations (since we never do one without the other) and make it
more robust for reads of uncached registers by bounds checking before we
look at the bitmap.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
This will bring no meaningful benefit by itself, it is done as a separate
commit to aid bisection if there are problems with the following commits
adding support for coalescing adjacent writes.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Mainly useful internally but exported since this is a public API that's
being checked for.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Provide a helper to do the size based index into a block of registers and
use it when reading a value.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This patch aims to bring down the average number of nodes
in the rbtree cache and increase the average number of registers
per node. This should improve general lookup and traversal times.
This is achieved by setting the minimum size of a block within the
rbnode to the size of the rbnode itself. This will essentially
cache possibly non-existent registers so to combat this scenario,
we keep a separate bitmap in memory which keeps track of which register
exists. The memory overhead of this change is likely in the order of
~5-10%, possibly less depending on the register file layout. On my test
system with a bitmap of ~4300 bits and a relatively sparse register
layout, the memory requirements for the entire cache did not increase
(the cutting down of nodes which was about 50% of the original number
compensated the situation).
A second patch that can be built on top of this can look at the
ratio `sizeof(*rbnode) / map->cache_word_size' in order to suitably
adjust the block length of each block.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This allows the cache to sync values directly to the device when stored
in native format and also allows asynchronous I/O.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.
To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.
At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Display the name for the chip rather than just the primary IRQ so it is
clearer what exactly has failed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The last register block, which falls into the specified range, is not handled
correctly. The formula which calculates the number of register which should be
synced is inverse (and off by one). E.g. if all registers in that block should
be synced only one is synced, and if only one should be synced all (but one) are
synced. To calculate the number of registers that need to be synced we need to
subtract the number of the first register in the block from the max register
number and add one. This patch updates the code accordingly.
The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync
operations").
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
