6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joy Chakraborty <joychakr@xxxxxxxxxx>
commit 28b008751aa295612318a0fbb2f22dd4f6a83139 upstream.
reg_read() callback registered with nvmem core expects 0 on success and
a negative value on error but rmem_read() returns the number of bytes
read which is treated as an error at the nvmem core.
This does not break when rmem is accessed using sysfs via
bin_attr_nvmem_read()/write() but causes an error when accessed from
places like nvmem_access_with_keepouts(), etc.
Change to return 0 on success and error in case
memory_read_from_buffer() returns an error or -EIO if bytes read do not
match what was requested.
Fixes: 5a3fa75a4d9c ("nvmem: Add driver to expose reserved memory as nvmem")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Joy Chakraborty <joychakr@xxxxxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240628113704.13742-2-srinivas.kandagatla@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvmem/rmem.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/nvmem/rmem.c
+++ b/drivers/nvmem/rmem.c
@@ -46,7 +46,10 @@ static int rmem_read(void *context, unsi
memunmap(addr);
- return count;
+ if (count < 0)
+ return count;
+
+ return count == bytes ? 0 : -EIO;
}
static int rmem_probe(struct platform_device *pdev)
