| 1 | From 5ca694dfd981a371e9b18cdd4a89c002ffaccbc5 Mon Sep 17 00:00:00 2001 |
| 2 | From: San Mehat <san@android.com> |
| 3 | Date: Wed, 3 Dec 2008 10:22:59 -0800 |
| 4 | Subject: [PATCH 099/134] mmc: mmcblk: Add new feature 'CONFIG_MMC_BLOCK_PARANOID_RESUME' |
| 5 | |
| 6 | With this feature enabled, mmcblk will check the card-status before issuing |
| 7 | a transaction *only* after being resumed. This protectes us from issuing |
| 8 | transactions before the sdcard is ready (which can occur if the host driver |
| 9 | deferrs mmc_resume_host() to reduce resume latency) |
| 10 | |
| 11 | Signed-off-by: San Mehat <san@android.com> |
| 12 | --- |
| 13 | drivers/mmc/card/Kconfig | 7 +++++++ |
| 14 | drivers/mmc/card/block.c | 3 +++ |
| 15 | drivers/mmc/card/queue.c | 28 ++++++++++++++++++++++++++++ |
| 16 | drivers/mmc/card/queue.h | 3 +++ |
| 17 | 4 files changed, 41 insertions(+), 0 deletions(-) |
| 18 | |
| 19 | --- a/drivers/mmc/card/Kconfig |
| 20 | +++ b/drivers/mmc/card/Kconfig |
| 21 | @@ -32,6 +32,13 @@ config MMC_BLOCK_BOUNCE |
| 22 | |
| 23 | If unsure, say Y here. |
| 24 | |
| 25 | +config MMC_BLOCK_PARANOID_RESUME |
| 26 | + bool "Check card status on resume" |
| 27 | + depends on MMC_BLOCK |
| 28 | + default y |
| 29 | + help |
| 30 | + Nohelp |
| 31 | + |
| 32 | config SDIO_UART |
| 33 | tristate "SDIO UART/GPS class support" |
| 34 | help |
| 35 | --- a/drivers/mmc/card/block.c |
| 36 | +++ b/drivers/mmc/card/block.c |
| 37 | @@ -643,6 +643,9 @@ static int mmc_blk_resume(struct mmc_car |
| 38 | |
| 39 | if (md) { |
| 40 | mmc_blk_set_blksize(md, card); |
| 41 | +#ifdef CONFIG_MMC_BLOCK_PARANOID_RESUME |
| 42 | + md->queue.check_status = 1; |
| 43 | +#endif |
| 44 | mmc_queue_resume(&md->queue); |
| 45 | } |
| 46 | return 0; |
| 47 | --- a/drivers/mmc/card/queue.c |
| 48 | +++ b/drivers/mmc/card/queue.c |
| 49 | @@ -14,7 +14,9 @@ |
| 50 | #include <linux/freezer.h> |
| 51 | #include <linux/kthread.h> |
| 52 | #include <linux/scatterlist.h> |
| 53 | +#include <linux/delay.h> |
| 54 | |
| 55 | +#include <linux/mmc/mmc.h> |
| 56 | #include <linux/mmc/card.h> |
| 57 | #include <linux/mmc/host.h> |
| 58 | #include "queue.h" |
| 59 | @@ -70,7 +72,33 @@ static int mmc_queue_thread(void *d) |
| 60 | continue; |
| 61 | } |
| 62 | set_current_state(TASK_RUNNING); |
| 63 | +#ifdef CONFIG_MMC_BLOCK_PARANOID_RESUME |
| 64 | + if (mq->check_status) { |
| 65 | + struct mmc_command cmd; |
| 66 | |
| 67 | + do { |
| 68 | + int err; |
| 69 | + |
| 70 | + cmd.opcode = MMC_SEND_STATUS; |
| 71 | + cmd.arg = mq->card->rca << 16; |
| 72 | + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; |
| 73 | + |
| 74 | + mmc_claim_host(mq->card->host); |
| 75 | + err = mmc_wait_for_cmd(mq->card->host, &cmd, 5); |
| 76 | + mmc_release_host(mq->card->host); |
| 77 | + |
| 78 | + if (err) { |
| 79 | + printk(KERN_ERR "%s: failed to get status (%d)\n", |
| 80 | + __func__, err); |
| 81 | + msleep(5); |
| 82 | + continue; |
| 83 | + } |
| 84 | + printk(KERN_DEBUG "%s: status 0x%.8x\n", __func__, cmd.resp[0]); |
| 85 | + } while (!(cmd.resp[0] & R1_READY_FOR_DATA) || |
| 86 | + (R1_CURRENT_STATE(cmd.resp[0]) == 7)); |
| 87 | + mq->check_status = 0; |
| 88 | + } |
| 89 | +#endif |
| 90 | mq->issue_fn(mq, req); |
| 91 | } while (1); |
| 92 | up(&mq->thread_sem); |
| 93 | --- a/drivers/mmc/card/queue.h |
| 94 | +++ b/drivers/mmc/card/queue.h |
| 95 | @@ -17,6 +17,9 @@ struct mmc_queue { |
| 96 | char *bounce_buf; |
| 97 | struct scatterlist *bounce_sg; |
| 98 | unsigned int bounce_sg_len; |
| 99 | +#ifdef CONFIG_MMC_BLOCK_PARANOID_RESUME |
| 100 | + int check_status; |
| 101 | +#endif |
| 102 | }; |
| 103 | |
| 104 | extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *); |
| 105 | |
