tequilaOS/platform_bootable_recovery
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

fix unnecessarily slow writing of EMMC partitions

Browse source 
These were attempts to write partitions "conservatively" in hopes of
fixing the problems with writing the radio partition on Nexus 4.  They
didn't work (a kernel patch was needed), but got left in.  They make
writing of partitions unnecessarily slow (ie, we really shouldn't need
to sync() after every 4kb).  Roll back most of them, but leave the
verification read-back in.

Change-Id: I94badc0979e88816c5aa0485f6316c02be69173c
This commit is contained in:
Doug Zongker 2013-12-19 15:16:57 -08:00
parent c87bab1018
commit 168724c31a
1 changed files with 3 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
applypatch/applypatch.c
View file

@ -424,20 +424,18 @@ int WriteToPartition(unsigned char* data, size_t len,
{ {
size_t start = 0; size_t start = 0;
int success = 0; int success = 0;
int fd = open(partition, O_RDWR | O_SYNC); int fd = open(partition, O_RDWR);
if (fd < 0) { if (fd < 0) {
printf("failed to open %s: %s\n", partition, strerror(errno)); printf("failed to open %s: %s\n", partition, strerror(errno));
return -1; return -1;
} }
int attempt; int attempt;
for (attempt = 0; attempt < 10; ++attempt) { for (attempt = 0; attempt < 2; ++attempt) {
size_t next_sync = start + (1<<20);
printf("raw O_SYNC write %s attempt %d start at %d\n", partition, attempt+1, start);
lseek(fd, start, SEEK_SET); lseek(fd, start, SEEK_SET);
while (start < len) { while (start < len) {
size_t to_write = len - start; size_t to_write = len - start;
if (to_write > 4096) to_write = 4096; if (to_write > 1<<20) to_write = 1<<20;
ssize_t written = write(fd, data+start, to_write); ssize_t written = write(fd, data+start, to_write);
if (written < 0) { if (written < 0) {
@ -450,10 +448,6 @@ int WriteToPartition(unsigned char* data, size_t len,
} }
} }
start += written; start += written;
if (start >= next_sync) {
fsync(fd);
next_sync = start + (1<<20);
}
} }
fsync(fd); fsync(fd);
@ -506,8 +500,6 @@ int WriteToPartition(unsigned char* data, size_t len,
success = true; success = true;
break; break;
} }
sleep(2);
} }
if (!success) { if (!success) {
@ -519,11 +511,7 @@ int WriteToPartition(unsigned char* data, size_t len,
printf("error closing %s (%s)\n", partition, strerror(errno)); printf("error closing %s (%s)\n", partition, strerror(errno));
return -1; return -1;
} }
// hack: sync and sleep after closing in hopes of getting
// the data actually onto flash.
printf("sleeping after close\n");
sync(); sync();
sleep(5);
break; break;
} }
} }