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Commit 81dcfe23 authored by Venkat Gopalakrishnan's avatar Venkat Gopalakrishnan
Browse files

mmc: debugfs: add debugfs entry to force raise host errors 



The SDHC spec allows to force raise errors that is useful for
debugging error handler routines. Add debugfs entry force_error
to trigger host errors from userspace. Check SDHCI_SET_INT_ERROR
register for error bitmask info.

Usage: echo 0x1 > /sys/kernel/debug/mmcX/force_error
X - denotes the slot id

Change-Id: I9f67442a79b2645cbdc3020d1a10c0b32840ce32
Signed-off-by: default avatarVenkat Gopalakrishnan <venkatg@codeaurora.org>
parent 50e0173f

drivers/mmc/core/debugfs.c

+19 −0
Original line number Diff line number Diff line
@@ -288,6 +288,21 @@ out: 
DEFINE_SIMPLE_ATTRIBUTE(mmc_max_clock_fops, mmc_max_clock_get,

		mmc_max_clock_set, "%llu\n");



static int mmc_force_err_set(void *data, u64 val)

{

	struct mmc_host *host = data;



	if (host && host->ops && host->ops->force_err_irq) {

		mmc_host_clk_hold(host);

		host->ops->force_err_irq(host, val);

		mmc_host_clk_release(host);

	}



	return 0;

}



DEFINE_SIMPLE_ATTRIBUTE(mmc_force_err_fops, NULL, mmc_force_err_set, "%llu\n");



void mmc_add_host_debugfs(struct mmc_host *host)

{

	struct dentry *root;
@@ -337,6 +352,10 @@ void mmc_add_host_debugfs(struct mmc_host *host) 
					     &host->fail_mmc_request)))

		goto err_node;

#endif

	if (!debugfs_create_file("force_error", S_IWUSR, root, host,

		&mmc_force_err_fops))

		goto err_node;



	return;



err_node:

drivers/mmc/host/sdhci.c

+13 −0
Original line number Diff line number Diff line
@@ -2608,6 +2608,18 @@ static int sdhci_late_init(struct mmc_host *mmc) 


	return 0;

}



static void sdhci_force_err_irq(struct mmc_host *mmc, u64 errmask)

{

	struct sdhci_host *host = mmc_priv(mmc);

	u16 mask = errmask & 0xFFFF;



	pr_err("%s: Force raise error mask:0x%04x\n", __func__, mask);

	sdhci_runtime_pm_get(host);

	sdhci_writew(host, mask, SDHCI_SET_INT_ERROR);

	sdhci_runtime_pm_put(host);

}



static const struct mmc_host_ops sdhci_ops = {

	.init           = sdhci_late_init,

	.pre_req	= sdhci_pre_req,
@@ -2628,6 +2640,7 @@ static const struct mmc_host_ops sdhci_ops = { 
	.notify_load	= sdhci_notify_load,

	.notify_halt	= sdhci_notify_halt,

	.detect		= sdhci_detect,

	.force_err_irq	= sdhci_force_err_irq,

};



/*****************************************************************************\

include/linux/mmc/host.h

+1 −0
Original line number Diff line number Diff line
@@ -178,6 +178,7 @@ struct mmc_host_ops { 
	int	(*notify_load)(struct mmc_host *, enum mmc_load);

	void	(*notify_halt)(struct mmc_host *mmc, bool halt);

	void	(*detect)(struct mmc_host *host, bool detected);

	void	(*force_err_irq)(struct mmc_host *host, u64 errmask);

};



struct mmc_card;