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authorDoug Thompson <dougthompson@xmission.com>2007-07-26 13:41:14 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-26 14:35:18 -0400
commitbce19683c17485b584b62b984d6dcf5332181588 (patch)
treeabc76c3fed9404df9cf3e636bc9f910c57e177dc /drivers/edac/edac_mc.c
parent045e72acf16054c4ed2760e9a8edb19a08053af1 (diff)
drivers/edac: fix reset edac_mc pollmsec
This fixes a deadlock that could occur on a 'setup' and 'teardown' sequence of the workq for a edac_mc control structure instance. A similiar fix was previously implemented for the edac_device code. In addition, the edac_mc device code there was missing code to allow the workq period valu to be altered via sysfs control. This patch adds that fix on the code, and allows for the changing of the period value as well. Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/edac/edac_mc.c')
-rw-r--r--drivers/edac/edac_mc.c64
1 files changed, 42 insertions, 22 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 4471be362599..063a1bffe38b 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -214,6 +214,13 @@ void edac_mc_free(struct mem_ctl_info *mci)
214} 214}
215EXPORT_SYMBOL_GPL(edac_mc_free); 215EXPORT_SYMBOL_GPL(edac_mc_free);
216 216
217
218/*
219 * find_mci_by_dev
220 *
221 * scan list of controllers looking for the one that manages
222 * the 'dev' device
223 */
217static struct mem_ctl_info *find_mci_by_dev(struct device *dev) 224static struct mem_ctl_info *find_mci_by_dev(struct device *dev)
218{ 225{
219 struct mem_ctl_info *mci; 226 struct mem_ctl_info *mci;
@@ -268,12 +275,6 @@ static void edac_mc_workq_function(struct work_struct *work_req)
268 if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL)) 275 if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL))
269 mci->edac_check(mci); 276 mci->edac_check(mci);
270 277
271 /*
272 * FIXME: temp place holder for PCI checks,
273 * goes away when we break out PCI
274 */
275 edac_pci_do_parity_check();
276
277 mutex_unlock(&mem_ctls_mutex); 278 mutex_unlock(&mem_ctls_mutex);
278 279
279 /* Reschedule */ 280 /* Reschedule */
@@ -314,36 +315,55 @@ static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
314{ 315{
315 int status; 316 int status;
316 317
317 /* if not running POLL, leave now */ 318 status = cancel_delayed_work(&mci->work);
318 if (mci->op_state == OP_RUNNING_POLL) { 319 if (status == 0) {
319 status = cancel_delayed_work(&mci->work); 320 debugf0("%s() not canceled, flush the queue\n",
320 if (status == 0) { 321 __func__);
321 debugf0("%s() not canceled, flush the queue\n",
322 __func__);
323 322
324 /* workq instance might be running, wait for it */ 323 /* workq instance might be running, wait for it */
325 flush_workqueue(edac_workqueue); 324 flush_workqueue(edac_workqueue);
326 }
327 } 325 }
328} 326}
329 327
330/* 328/*
331 * edac_reset_delay_period 329 * edac_mc_reset_delay_period(unsigned long value)
330 *
331 * user space has updated our poll period value, need to
332 * reset our workq delays
332 */ 333 */
333static void edac_reset_delay_period(struct mem_ctl_info *mci, unsigned long value) 334void edac_mc_reset_delay_period(int value)
334{ 335{
335 /* cancel the current workq request */ 336 struct mem_ctl_info *mci;
336 edac_mc_workq_teardown(mci); 337 struct list_head *item;
337 338
338 /* lock the list of devices for the new setup */
339 mutex_lock(&mem_ctls_mutex); 339 mutex_lock(&mem_ctls_mutex);
340 340
341 /* restart the workq request, with new delay value */ 341 /* scan the list and turn off all workq timers, doing so under lock
342 edac_mc_workq_setup(mci, value); 342 */
343 list_for_each(item, &mc_devices) {
344 mci = list_entry(item, struct mem_ctl_info, link);
345
346 if (mci->op_state == OP_RUNNING_POLL)
347 cancel_delayed_work(&mci->work);
348 }
349
350 mutex_unlock(&mem_ctls_mutex);
351
352
353 /* re-walk the list, and reset the poll delay */
354 mutex_lock(&mem_ctls_mutex);
355
356 list_for_each(item, &mc_devices) {
357 mci = list_entry(item, struct mem_ctl_info, link);
358
359 edac_mc_workq_setup(mci, (unsigned long) value);
360 }
343 361
344 mutex_unlock(&mem_ctls_mutex); 362 mutex_unlock(&mem_ctls_mutex);
345} 363}
346 364
365
366
347/* Return 0 on success, 1 on failure. 367/* Return 0 on success, 1 on failure.
348 * Before calling this function, caller must 368 * Before calling this function, caller must
349 * assign a unique value to mci->mc_idx. 369 * assign a unique value to mci->mc_idx.