From 3caf41406dd67b412abae7df86cc2a09bef9621f Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Wed, 6 Jun 2012 09:45:50 -0400 Subject: [PATCH] mmc: omap: Fix NULL pointer dereference if mmc_omap_new_slot() fails Commit b01a4f1c (mmc: omap: convert to per instance workqueue) initializes the workqueue too late causing the following: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 Not tainted (3.4.0-08218-gb48b2c3 #158) PC is at __queue_work+0x8/0x46c LR is at queue_work_on+0x38/0x40 pc : [] lr : [] psr: 60000193 sp : c0691e1c ip : 00000000 fp : c07374ac r10: c7aae400 r9 : c0395700 r8 : 00000100 r7 : c0691e70 r6 : 00000000 r5 : 00000000 r4 : c7aae440 r3 : 00000001 r2 : c7aae440 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 00c5387d Table: 80004000 DAC: 00000017 Process swapper/0 (pid: 0, stack limit = 0xc06902f8) Stack: (0xc0691e1c to 0xc0692000) Fix this by initializing the workqueue before mmc_omap_remove_slot() get called. Tested on n770, looks like n800 at least still has some other issue with MMC. Signed-off-by: Tony Lindgren Signed-off-by: Chris Ball --- drivers/mmc/host/omap.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c index feda3064b2cd..6b07730598da 100644 --- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -1485,24 +1485,27 @@ static int __devinit mmc_omap_probe(struct platform_device *pdev) } host->nr_slots = pdata->nr_slots; + + host->mmc_omap_wq = alloc_workqueue("mmc_omap", 0, 0); + if (!host->mmc_omap_wq) + goto err_plat_cleanup; + for (i = 0; i < pdata->nr_slots; i++) { ret = mmc_omap_new_slot(host, i); if (ret < 0) { while (--i >= 0) mmc_omap_remove_slot(host->slots[i]); - goto err_plat_cleanup; + goto err_destroy_wq; } } host->reg_shift = (cpu_is_omap7xx() ? 1 : 2); - host->mmc_omap_wq = alloc_workqueue("mmc_omap", 0, 0); - if (!host->mmc_omap_wq) - goto err_plat_cleanup; - return 0; +err_destroy_wq: + destroy_workqueue(host->mmc_omap_wq); err_plat_cleanup: if (pdata->cleanup) pdata->cleanup(&pdev->dev);