Commit 4f665cb6 authored by Yoshihiro Shimoda's avatar Yoshihiro Shimoda Committed by Chris Ball
Browse files

mmc: fix mmc_app_send_scr() for dma transfer 



This patch is based on the commit "af517150":

   * Bugfix to that mmc_send_cxd_data() code:  dma-to-stack is
     unsafe/nonportable, so kmalloc a bounce buffer instead.

The driver may invalidate the mmc_card->csd when host driver uses dma.
So this subroutine also needs a kmalloc buffer.

Signed-off-by: default avatarYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 58ac8177

drivers/mmc/core/sd_ops.c

+13 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
 * your option) any later version.

 */



#include <linux/slab.h>

#include <linux/types.h>

#include <linux/scatterlist.h>
@@ -252,6 +253,7 @@ int mmc_app_send_scr(struct mmc_card *card, u32 *scr) 
	struct mmc_command cmd;

	struct mmc_data data;

	struct scatterlist sg;

	void *data_buf;



	BUG_ON(!card);

	BUG_ON(!card->host);
@@ -263,6 +265,13 @@ int mmc_app_send_scr(struct mmc_card *card, u32 *scr) 
	if (err)

		return err;



	/* dma onto stack is unsafe/nonportable, but callers to this

	 * routine normally provide temporary on-stack buffers ...

	 */

	data_buf = kmalloc(sizeof(card->raw_scr), GFP_KERNEL);

	if (data_buf == NULL)

		return -ENOMEM;



	memset(&mrq, 0, sizeof(struct mmc_request));

	memset(&cmd, 0, sizeof(struct mmc_command));

	memset(&data, 0, sizeof(struct mmc_data));
@@ -280,12 +289,15 @@ int mmc_app_send_scr(struct mmc_card *card, u32 *scr) 
	data.sg = &sg;

	data.sg_len = 1;



	sg_init_one(&sg, scr, 8);

	sg_init_one(&sg, data_buf, 8);



	mmc_set_data_timeout(&data, card);



	mmc_wait_for_req(card->host, &mrq);



	memcpy(scr, data_buf, sizeof(card->raw_scr));

	kfree(data_buf);



	if (cmd.error)

		return cmd.error;

	if (data.error)

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