lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

mmc: Test bus-width for old MMC devices

Browse Source 
Some old MMC devices fail with the 4/8 bits the driver tries to use
exclusively.  This patch adds a test for the given bus setup and falls
back to the lower bit mode (until 1-bit mode) when the test fails.

[Major rework and refactoring by tiwai]
[Quirk addition and many fixes by prakity]

Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Aries Lee
2010-12-15 08:14:24 +01:00
committed by Chris Ball
parent e6f29a8dc1
commit 22113efd00
7 changed files with 158 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

101
drivers/mmc/core/mmc_ops.c
View File

@@ -462,3 +462,104 @@ int mmc_send_status(struct mmc_card *card, u32 *status)
return 0;
}
static int
mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
u8 len)
{
struct mmc_request mrq;
struct mmc_command cmd;
struct mmc_data data;
struct scatterlist sg;
u8 *data_buf;
u8 *test_buf;
int i, err;
static u8 testdata_8bit[8] = { 0x55, 0xaa, 0, 0, 0, 0, 0, 0 };
static u8 testdata_4bit[4] = { 0x5a, 0, 0, 0 };
/* dma onto stack is unsafe/nonportable, but callers to this
* routine normally provide temporary on-stack buffers ...
*/
data_buf = kmalloc(len, GFP_KERNEL);
if (!data_buf)
return -ENOMEM;
if (len == 8)
test_buf = testdata_8bit;
else if (len == 4)
test_buf = testdata_4bit;
else {
printk(KERN_ERR "%s: Invalid bus_width %d\n",
mmc_hostname(host), len);
kfree(data_buf);
return -EINVAL;
}
if (opcode == MMC_BUS_TEST_W)
memcpy(data_buf, test_buf, len);
memset(&mrq, 0, sizeof(struct mmc_request));
memset(&cmd, 0, sizeof(struct mmc_command));
memset(&data, 0, sizeof(struct mmc_data));
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = opcode;
cmd.arg = 0;
/* NOTE HACK: the MMC_RSP_SPI_R1 is always correct here, but we
* rely on callers to never use this with "native" calls for reading
* CSD or CID. Native versions of those commands use the R2 type,
* not R1 plus a data block.
*/
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = len;
data.blocks = 1;
if (opcode == MMC_BUS_TEST_R)
data.flags = MMC_DATA_READ;
else
data.flags = MMC_DATA_WRITE;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, data_buf, len);
mmc_wait_for_req(host, &mrq);
err = 0;
if (opcode == MMC_BUS_TEST_R) {
for (i = 0; i < len / 4; i++)
if ((test_buf[i] ^ data_buf[i]) != 0xff) {
err = -EIO;
break;
}
}
kfree(data_buf);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
return err;
}
int mmc_bus_test(struct mmc_card *card, u8 bus_width)
{
int err, width;
if (bus_width == MMC_BUS_WIDTH_8)
width = 8;
else if (bus_width == MMC_BUS_WIDTH_4)
width = 4;
else if (bus_width == MMC_BUS_WIDTH_1)
return 0; /* no need for test */
else
return -EINVAL;
/*
* Ignore errors from BUS_TEST_W. BUS_TEST_R will fail if there
* is a problem. This improves chances that the test will work.
*/
mmc_send_bus_test(card, card->host, MMC_BUS_TEST_W, width);
err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
return err;
}