From 6ce0a856c10c8ab8568764436864616efa88e908 Mon Sep 17 00:00:00 2001 From: Richard Purdie Date: Tue, 29 Jan 2008 11:27:11 +0000 Subject: [PATCH] [MTD] mtdoops: Perform write operations in a workqueue Writing to the flash needs to be done in a workqueue. The console write functions may be called in any context which can lead to lockups otherwise. Signed-off-by: Richard Purdie Signed-off-by: David Woodhouse --- drivers/mtd/mtdoops.c | 82 ++++++++++++++++++++++--------------------- 1 file changed, 42 insertions(+), 40 deletions(-) diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index 723ca76d6b55..72c434c61b0a 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -32,9 +32,10 @@ #define OOPS_PAGE_SIZE 4096 -static struct mtdoops_context { +struct mtdoops_context { int mtd_index; - struct work_struct work; + struct work_struct work_erase; + struct work_struct work_write; struct mtd_info *mtd; int oops_pages; int nextpage; @@ -87,7 +88,7 @@ static int mtdoops_erase_block(struct mtd_info *mtd, int offset) return 0; } -static int mtdoops_inc_counter(struct mtdoops_context *cxt) +static void mtdoops_inc_counter(struct mtdoops_context *cxt) { struct mtd_info *mtd = cxt->mtd; size_t retlen; @@ -107,21 +108,26 @@ static int mtdoops_inc_counter(struct mtdoops_context *cxt) printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)" ", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE, retlen, ret); - return 1; + schedule_work(&cxt->work_erase); + return; } /* See if we need to erase the next block */ - if (count != 0xffffffff) - return 1; + if (count != 0xffffffff) { + schedule_work(&cxt->work_erase); + return; + } printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n", cxt->nextpage, cxt->nextcount); cxt->ready = 1; - return 0; } -static void mtdoops_prepare(struct mtdoops_context *cxt) +/* Scheduled work - when we can't proceed without erasing a block */ +static void mtdoops_workfunc_erase(struct work_struct *work) { + struct mtdoops_context *cxt = + container_of(work, struct mtdoops_context, work_erase); struct mtd_info *mtd = cxt->mtd; int i = 0, j, ret, mod; @@ -176,15 +182,31 @@ static void mtdoops_prepare(struct mtdoops_context *cxt) goto badblock; } -static void mtdoops_workfunc(struct work_struct *work) +static void mtdoops_workfunc_write(struct work_struct *work) { struct mtdoops_context *cxt = - container_of(work, struct mtdoops_context, work); + container_of(work, struct mtdoops_context, work_write); + struct mtd_info *mtd = cxt->mtd; + size_t retlen; + int ret; - mtdoops_prepare(cxt); -} + if (cxt->writecount < OOPS_PAGE_SIZE) + memset(cxt->oops_buf + cxt->writecount, 0xff, + OOPS_PAGE_SIZE - cxt->writecount); + + ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE, + OOPS_PAGE_SIZE, &retlen, cxt->oops_buf); + + cxt->writecount = 0; + + if ((retlen != OOPS_PAGE_SIZE) || (ret < 0)) + printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n", + cxt->nextpage * OOPS_PAGE_SIZE, retlen, OOPS_PAGE_SIZE, ret); + + mtdoops_inc_counter(cxt); +} -static int find_next_position(struct mtdoops_context *cxt) +static void find_next_position(struct mtdoops_context *cxt) { struct mtd_info *mtd = cxt->mtd; int ret, page, maxpos = 0; @@ -222,20 +244,19 @@ static int find_next_position(struct mtdoops_context *cxt) cxt->ready = 1; printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n", cxt->nextpage, cxt->nextcount); - return 0; + return; } cxt->nextpage = maxpos; cxt->nextcount = maxcount; - return mtdoops_inc_counter(cxt); + mtdoops_inc_counter(cxt); } static void mtdoops_notify_add(struct mtd_info *mtd) { struct mtdoops_context *cxt = &oops_cxt; - int ret; if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0) return; @@ -249,9 +270,7 @@ static void mtdoops_notify_add(struct mtd_info *mtd) cxt->mtd = mtd; cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE; - ret = find_next_position(cxt); - if (ret == 1) - mtdoops_prepare(cxt); + find_next_position(cxt); printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index); } @@ -271,31 +290,13 @@ static void mtdoops_console_sync(void) { struct mtdoops_context *cxt = &oops_cxt; struct mtd_info *mtd = cxt->mtd; - size_t retlen; - int ret; - if (!cxt->ready || !mtd) + if (!cxt->ready || !mtd || cxt->writecount == 0) return; - if (cxt->writecount == 0) - return; - - if (cxt->writecount < OOPS_PAGE_SIZE) - memset(cxt->oops_buf + cxt->writecount, 0xff, - OOPS_PAGE_SIZE - cxt->writecount); - - ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE, - OOPS_PAGE_SIZE, &retlen, cxt->oops_buf); cxt->ready = 0; - cxt->writecount = 0; - - if ((retlen != OOPS_PAGE_SIZE) || (ret < 0)) - printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n", - cxt->nextpage * OOPS_PAGE_SIZE, retlen, OOPS_PAGE_SIZE, ret); - ret = mtdoops_inc_counter(cxt); - if (ret == 1) - schedule_work(&cxt->work); + schedule_work(&cxt->work_write); } static void @@ -365,7 +366,8 @@ static int __init mtdoops_console_init(void) return -ENOMEM; } - INIT_WORK(&cxt->work, mtdoops_workfunc); + INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); + INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); register_console(&mtdoops_console); register_mtd_user(&mtdoops_notifier); -- GitLab