d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[ig4] Add support for polled mode

Browse Source 
Currently ig4 internally depends on it's own interrupts and uses mtx_sleep()
to wait for them. That means it can not be used from any context where
sleeping is disallowed e.g. on cold boot, from DDB/KDB, from other device
driver's interrupt handlers and so on.

This change replaces sleeps with busy loops in cold boot and DDB cases.
This commit is contained in:
wulf 2019-11-03 20:51:22 +00:00
parent f03318a994
commit 799fd2ee8e
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
sys/dev/ichiic/ig4_iic.c
View File

@ -48,8 +48,10 @@ __FBSDID("$FreeBSD$");
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/errno.h>
#include <sys/kdb.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sx.h>
#include <sys/syslog.h>
#include <sys/bus.h>
@ -70,6 +72,8 @@ __FBSDID("$FreeBSD$");
#define TRANS_PCALL 2
#define TRANS_BLOCK 3
#define DO_POLL(sc) (cold || kdb_active || SCHEDULER_STOPPED())
static void ig4iic_start(void *xdev);
static void ig4iic_intr(void *cookie);
static void ig4iic_dump(ig4iic_softc_t *sc);
@ -187,7 +191,7 @@ wait_status(ig4iic_softc_t *sc, uint32_t status)
* When waiting for receive data let the interrupt do its
* work, otherwise poll with the lock held.
*/
if (status & IG4_STATUS_RX_NOTEMPTY) {
if ((status & IG4_STATUS_RX_NOTEMPTY) && !DO_POLL(sc)) {
mtx_lock(&sc->io_lock);
set_intr_mask(sc, IG4_INTR_STOP_DET | IG4_INTR_RX_FULL);
mtx_sleep(sc, &sc->io_lock, 0, "i2cwait",