evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

mmc: host: Fix spinbug in performance sysfs nodes

Browse source 
In CMDQ, the mmc_release_host runs in softirq context.
There's a potential race condition between show/set_perf
since it doesn't disable pre-emption. Change this to
disable preemption.

Change-Id: I20918a459e8b35ac666971b8ebf179f44aa9c40f
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
This commit is contained in:
Asutosh Das 2015-05-18 10:55:01 +05:30 • committed by Subhash Jadavani
parent 4d105602c4
commit b099847e11
1 changed files with 6 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
drivers/mmc/core/host.c
View file

@ -776,9 +776,9 @@ show_perf(struct device *dev, struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int64_t rtime_drv, wtime_drv;
unsigned long rbytes_drv, wbytes_drv;
unsigned long rbytes_drv, wbytes_drv, flags;
spin_lock(&host->lock);
spin_lock_irqsave(&host->lock, flags);
rbytes_drv = host->perf.rbytes_drv;
wbytes_drv = host->perf.wbytes_drv;
@ -786,7 +786,7 @@ show_perf(struct device *dev, struct device_attribute *attr, char *buf)
rtime_drv = ktime_to_us(host->perf.rtime_drv);
wtime_drv = ktime_to_us(host->perf.wtime_drv);
spin_unlock(&host->lock);
spin_unlock_irqrestore(&host->lock, flags);
return snprintf(buf, PAGE_SIZE, "Write performance at driver Level:"
"%lu bytes in %lld microseconds\n"
@ -802,16 +802,17 @@ set_perf(struct device *dev, struct device_attribute *attr,
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int64_t value;
unsigned long flags;
sscanf(buf, "%lld", &value);
spin_lock(&host->lock);
spin_lock_irqsave(&host->lock, flags);
if (!value) {
memset(&host->perf, 0, sizeof(host->perf));
host->perf_enable = false;
} else {
host->perf_enable = true;
}
spin_unlock(&host->lock);
spin_unlock_irqrestore(&host->lock, flags);
return count;
}