Mirrors/u-boot
2
0
Fork 0
mirror of https://github.com/AsahiLinux/u-boot synced 2024-11-10 07:04:28 +00:00
Code Issues Projects Releases Packages Wiki Activity

fw_env: keep calling read() until whole flash block is read

Browse source 
It's totally valid for read() to provide less bytes than requested
maximum. It may happen if there is no more data available yet or source
pushes data in small chunks.

This actually happens when trying to read env data from NVMEM device.
Kernel may provide NVMEM content in page size parts (like 4096 B).

This fixes warnings like:
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 16384 bytes but got 4096
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 12288 bytes but got 4096
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 8192 bytes but got 4096

Since the main loop in flash_read_buf() is used to read blocks this
patch adds a new nested one.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki 2023-12-13 13:13:54 +01:00 committed by Tom Rini
parent 73b30800f5
commit 9e3003f79d
1 changed files with 15 additions and 19 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

34
tools/env/fw_env.c vendored
View file

@ -948,29 +948,25 @@ static int flash_read_buf(int dev, int fd, void *buf, size_t count,
*/
lseek(fd, blockstart + block_seek, SEEK_SET);
rc = read(fd, buf + processed, readlen);
if (rc == -1) {
fprintf(stderr, "Read error on %s: %s\n",
DEVNAME(dev), strerror(errno));
return -1;
}
while (readlen) {
rc = read(fd, buf + processed, readlen);
if (rc == -1) {
fprintf(stderr, "Read error on %s: %s\n",
DEVNAME(dev), strerror(errno));
return -1;
}
#ifdef DEBUG
fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
rc, (unsigned long long)blockstart + block_seek,
DEVNAME(dev));
fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
rc, (unsigned long long)blockstart + block_seek,
DEVNAME(dev));
#endif
processed += rc;
if (rc != readlen) {
fprintf(stderr,
"Warning on %s: Attempted to read %zd bytes but got %d\n",
DEVNAME(dev), readlen, rc);
processed += rc;
readlen -= rc;
block_seek += rc;
} else {
blockstart += blocklen;
readlen = min(blocklen, count - processed);
block_seek = 0;
}
blockstart += blocklen;
readlen = min(blocklen, count - processed);
block_seek = 0;
}
return processed;