Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9840fcd8 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

fsi: Prevent multiple concurrent rescans 



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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent d1dcd678

drivers/fsi/fsi-core.c

+14 −2
Original line number Diff line number Diff line
@@ -1203,8 +1203,14 @@ static void fsi_master_unscan(struct fsi_master *master) 


int fsi_master_rescan(struct fsi_master *master)

{

	int rc;



	mutex_lock(&master->scan_lock);

	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);
@@ -1240,6 +1246,7 @@ int fsi_master_register(struct fsi_master *master) 
	int rc;

	struct device_node *np;



	mutex_init(&master->scan_lock);

	master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);

	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);

	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);

		mutex_unlock(&master->scan_lock);

	}



	return 0;

}
@@ -1278,7 +1288,9 @@ void fsi_master_unregister(struct fsi_master *master) 
		master->idx = -1;

	}



	mutex_lock(&master->scan_lock);

	fsi_master_unscan(master);

	mutex_unlock(&master->scan_lock);

	device_unregister(&master->dev);

}

EXPORT_SYMBOL_GPL(fsi_master_unregister);

drivers/fsi/fsi-master.h

+2 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#define DRIVERS_FSI_MASTER_H



#include <linux/device.h>

#include <linux/mutex.h>



/* Various protocol delays */

#define	FSI_ECHO_DELAY_CLOCKS	16	/* Number clocks for echo delay */
@@ -59,6 +60,7 @@ struct fsi_master { 
	int		idx;

	int		n_links;

	int		flags;

	struct mutex	scan_lock;

	int		(*read)(struct fsi_master *, int link, uint8_t id,

				uint32_t addr, void *val, size_t size);

	int		(*write)(struct fsi_master *, int link, uint8_t id,