rslib: Update documentation

The decoder returns the number of corrected symbols, not bits.
The caller provided syndrome must be in index form.

Signed-off-by: Ferdinand Blomqvist <ferdinand.blomqvist@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190620141039.9874-7-ferdinand.blomqvist@gmail.com

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/reed_solomon/reed_solomon.c b/lib/reed_solomon/reed_solomon.c
index e5fdc8b9e856..bbc01bad3053 100644
--- a/lib/reed_solomon/reed_solomon.c
+++ b/lib/reed_solomon/reed_solomon.c
@@ -340,7 +340,8 @@ EXPORT_SYMBOL_GPL(encode_rs8);
  *  @data:      data field of a given type
  *  @par:       received parity data field
  *  @len:       data length
- *  @s:         syndrome data field (if NULL, syndrome is calculated)
+ *  @s:         syndrome data field, must be in index form
+ *              (if NULL, syndrome is calculated)
  *  @no_eras:   number of erasures
  *  @eras_pos:  position of erasures, can be NULL
  *  @invmsk:    invert data mask (will be xored on data, not on parity!)
@@ -354,7 +355,8 @@ EXPORT_SYMBOL_GPL(encode_rs8);
  *  decoding, so the caller has to ensure that decoder invocations are
  *  serialized.
  *
- *  Returns the number of corrected bits or -EBADMSG for uncorrectable errors.
+ *  Returns the number of corrected symbols or -EBADMSG for uncorrectable
+ *  errors. The count includes errors in the parity.
  */
 int decode_rs8(struct rs_control *rsc, uint8_t *data, uint16_t *par, int len,
                uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
@@ -391,7 +393,8 @@ EXPORT_SYMBOL_GPL(encode_rs16);
  *  @data:      data field of a given type
  *  @par:       received parity data field
  *  @len:       data length
- *  @s:         syndrome data field (if NULL, syndrome is calculated)
+ *  @s:         syndrome data field, must be in index form
+ *              (if NULL, syndrome is calculated)
  *  @no_eras:   number of erasures
  *  @eras_pos:  position of erasures, can be NULL
  *  @invmsk:    invert data mask (will be xored on data, not on parity!)
@@ -403,7 +406,8 @@ EXPORT_SYMBOL_GPL(encode_rs16);
  *  decoding, so the caller has to ensure that decoder invocations are
  *  serialized.
  *
- *  Returns the number of corrected bits or -EBADMSG for uncorrectable errors.
+ *  Returns the number of corrected symbols or -EBADMSG for uncorrectable
+ *  errors. The count includes errors in the parity.
  */
 int decode_rs16(struct rs_control *rsc, uint16_t *data, uint16_t *par, int len,
                 uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,