ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 20:51:03 +02:00
Code Issues Packages Projects Releases Wiki Activity

fsi: Prevent multiple concurrent rescans

Browse Source 
The bus scanning process isn't terribly good at parallel attempts
at rescanning the same bus. Let's have a per-master mutex protecting
the scanning process.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt
2018-06-21 18:00:05 +10:00
parent d1dcd67825
commit 9840fcd8cc
2 changed files with 16 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/fsi/fsi-core.c
View File

@@ -1203,8 +1203,14 @@ static void fsi_master_unscan(struct fsi_master *master)
int fsi_master_rescan(struct fsi_master *master) int fsi_master_rescan(struct fsi_master *master)
{ {
int rc;
mutex_lock(&master->scan_lock);
fsi_master_unscan(master); fsi_master_unscan(master);
return fsi_master_scan(master); rc = fsi_master_scan(master);
mutex_unlock(&master->scan_lock);
return rc;
} }
EXPORT_SYMBOL_GPL(fsi_master_rescan); EXPORT_SYMBOL_GPL(fsi_master_rescan);
@@ -1240,6 +1246,7 @@ int fsi_master_register(struct fsi_master *master)
int rc; int rc;
struct device_node *np; struct device_node *np;
mutex_init(&master->scan_lock);
master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
dev_set_name(&master->dev, "fsi%d", master->idx); dev_set_name(&master->dev, "fsi%d", master->idx);
@@ -1264,8 +1271,11 @@ int fsi_master_register(struct fsi_master *master)
} }
np = dev_of_node(&master->dev); np = dev_of_node(&master->dev);
if (!of_property_read_bool(np, "no-scan-on-init")) if (!of_property_read_bool(np, "no-scan-on-init")) {
mutex_lock(&master->scan_lock);
fsi_master_scan(master); fsi_master_scan(master);
mutex_unlock(&master->scan_lock);
}
return 0; return 0;
} }
@@ -1278,7 +1288,9 @@ void fsi_master_unregister(struct fsi_master *master)
master->idx = -1; master->idx = -1;
} }
mutex_lock(&master->scan_lock);
fsi_master_unscan(master); fsi_master_unscan(master);
mutex_unlock(&master->scan_lock);
device_unregister(&master->dev); device_unregister(&master->dev);
} }
EXPORT_SYMBOL_GPL(fsi_master_unregister); EXPORT_SYMBOL_GPL(fsi_master_unregister);

2
drivers/fsi/fsi-master.h
View File

@@ -18,6 +18,7 @@
#define DRIVERS_FSI_MASTER_H #define DRIVERS_FSI_MASTER_H
#include <linux/device.h> #include <linux/device.h>
#include <linux/mutex.h>
/* Various protocol delays */ /* Various protocol delays */
#define FSI_ECHO_DELAY_CLOCKS 16 /* Number clocks for echo delay */ #define FSI_ECHO_DELAY_CLOCKS 16 /* Number clocks for echo delay */
@@ -59,6 +60,7 @@ struct fsi_master {
int idx; int idx;
int n_links; int n_links;
int flags; int flags;
struct mutex scan_lock;
int (*read)(struct fsi_master *, int link, uint8_t id, int (*read)(struct fsi_master *, int link, uint8_t id,
uint32_t addr, void *val, size_t size); uint32_t addr, void *val, size_t size);
int (*write)(struct fsi_master *, int link, uint8_t id, int (*write)(struct fsi_master *, int link, uint8_t id,