Commit 3caf4140 authored Jun 06, 2012 by Tony Lindgren Committed by Chris Ball Jun 06, 2012

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 : [<c005bb4c>]    lr : [<c005c00c>]    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 <tony@atomide.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

parent 4f837791

drivers/mmc/host/omap.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -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);

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