mmc: remove multiwrite capability
Relax requirements on host controllers and only require that they do not
report a transfer count than is larger than the actual one (i.e. a lower
value is okay). This is how many other parts of the kernel behaves so
upper layers should already be prepared to handle that scenario. This
gives us a performance boost on MMC cards.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 4b0f822..66e5a54 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -237,17 +237,6 @@
if (brq.data.blocks > card->host->max_blk_count)
brq.data.blocks = card->host->max_blk_count;
- /*
- * If the host doesn't support multiple block writes, force
- * block writes to single block. SD cards are excepted from
- * this rule as they support querying the number of
- * successfully written sectors.
- */
- if (rq_data_dir(req) != READ &&
- !(card->host->caps & MMC_CAP_MULTIWRITE) &&
- !mmc_card_sd(card))
- brq.data.blocks = 1;
-
if (brq.data.blocks > 1) {
/* SPI multiblock writes terminate using a special
* token, not a STOP_TRANSMISSION request.
@@ -367,30 +356,32 @@
* mark the known good sectors as ok.
*
* If the card is not SD, we can still ok written sectors
- * if the controller can do proper error reporting.
+ * as reported by the controller (which might be less than
+ * the real number of written sectors, but never more).
*
* For reads we just fail the entire chunk as that should
* be safe in all cases.
*/
- if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
- u32 blocks;
- unsigned int bytes;
+ if (rq_data_dir(req) != READ) {
+ if (mmc_card_sd(card)) {
+ u32 blocks;
+ unsigned int bytes;
- blocks = mmc_sd_num_wr_blocks(card);
- if (blocks != (u32)-1) {
- if (card->csd.write_partial)
- bytes = blocks << md->block_bits;
- else
- bytes = blocks << 9;
+ blocks = mmc_sd_num_wr_blocks(card);
+ if (blocks != (u32)-1) {
+ if (card->csd.write_partial)
+ bytes = blocks << md->block_bits;
+ else
+ bytes = blocks << 9;
+ spin_lock_irq(&md->lock);
+ ret = __blk_end_request(req, 0, bytes);
+ spin_unlock_irq(&md->lock);
+ }
+ } else {
spin_lock_irq(&md->lock);
- ret = __blk_end_request(req, 0, bytes);
+ ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
spin_unlock_irq(&md->lock);
}
- } else if (rq_data_dir(req) != READ &&
- (card->host->caps & MMC_CAP_MULTIWRITE)) {
- spin_lock_irq(&md->lock);
- ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
- spin_unlock_irq(&md->lock);
}
mmc_release_host(card->host);
diff --git a/drivers/mmc/host/at91_mci.c b/drivers/mmc/host/at91_mci.c
index 16df235..f15e206 100644
--- a/drivers/mmc/host/at91_mci.c
+++ b/drivers/mmc/host/at91_mci.c
@@ -995,7 +995,7 @@
mmc->f_min = 375000;
mmc->f_max = 25000000;
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
- mmc->caps = MMC_CAP_MULTIWRITE | MMC_CAP_SDIO_IRQ;
+ mmc->caps = MMC_CAP_SDIO_IRQ;
mmc->max_blk_size = 4095;
mmc->max_blk_count = mmc->max_req_size;
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 25d5324a..cce873c 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -849,7 +849,7 @@
mmc->f_min = (host->bus_hz + 511) / 512;
mmc->f_max = host->bus_hz / 2;
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
- mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_MULTIWRITE;
+ mmc->caps |= MMC_CAP_4_BIT_DATA;
mmc->max_hw_segs = 64;
mmc->max_phys_segs = 64;
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 4e82f64..41cc633 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1252,10 +1252,7 @@
mmc->ops = &mmc_spi_ops;
mmc->max_blk_size = MMC_SPI_BLOCKSIZE;
- /* As long as we keep track of the number of successfully
- * transmitted blocks, we're good for multiwrite.
- */
- mmc->caps = MMC_CAP_SPI | MMC_CAP_MULTIWRITE;
+ mmc->caps = MMC_CAP_SPI;
/* SPI doesn't need the lowspeed device identification thing for
* MMC or SD cards, since it never comes up in open drain mode.
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index da5feca..696cf36 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -535,7 +535,6 @@
mmc->f_min = (host->mclk + 511) / 512;
mmc->f_max = min(host->mclk, fmax);
mmc->ocr_avail = plat->ocr_mask;
- mmc->caps = MMC_CAP_MULTIWRITE;
/*
* We can do SGIO
diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c
index 549517c..dbc26eb6 100644
--- a/drivers/mmc/host/omap.c
+++ b/drivers/mmc/host/omap.c
@@ -1317,7 +1317,7 @@
host->slots[id] = slot;
- mmc->caps = MMC_CAP_MULTIWRITE;
+ mmc->caps = 0;
if (host->pdata->conf.wire4)
mmc->caps |= MMC_CAP_4_BIT_DATA;
diff --git a/drivers/mmc/host/tifm_sd.c b/drivers/mmc/host/tifm_sd.c
index 1c14a18..1384484 100644
--- a/drivers/mmc/host/tifm_sd.c
+++ b/drivers/mmc/host/tifm_sd.c
@@ -973,7 +973,7 @@
mmc->ops = &tifm_sd_ops;
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
- mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_MULTIWRITE;
+ mmc->caps = MMC_CAP_4_BIT_DATA;
mmc->f_min = 20000000 / 60;
mmc->f_max = 24000000;
diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index f7dcd8e..adda379 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1219,7 +1219,7 @@
mmc->f_min = 375000;
mmc->f_max = 24000000;
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
- mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_MULTIWRITE;
+ mmc->caps = MMC_CAP_4_BIT_DATA;
spin_lock_init(&host->lock);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 753b723..10a2080 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -111,12 +111,11 @@
unsigned long caps; /* Host capabilities */
#define MMC_CAP_4_BIT_DATA (1 << 0) /* Can the host do 4 bit transfers */
-#define MMC_CAP_MULTIWRITE (1 << 1) /* Can accurately report bytes sent to card on error */
-#define MMC_CAP_MMC_HIGHSPEED (1 << 2) /* Can do MMC high-speed timing */
-#define MMC_CAP_SD_HIGHSPEED (1 << 3) /* Can do SD high-speed timing */
-#define MMC_CAP_SDIO_IRQ (1 << 4) /* Can signal pending SDIO IRQs */
-#define MMC_CAP_SPI (1 << 5) /* Talks only SPI protocols */
-#define MMC_CAP_NEEDS_POLL (1 << 6) /* Needs polling for card-detection */
+#define MMC_CAP_MMC_HIGHSPEED (1 << 1) /* Can do MMC high-speed timing */
+#define MMC_CAP_SD_HIGHSPEED (1 << 2) /* Can do SD high-speed timing */
+#define MMC_CAP_SDIO_IRQ (1 << 3) /* Can signal pending SDIO IRQs */
+#define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */
+#define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */
/* host specific block data */
unsigned int max_seg_size; /* see blk_queue_max_segment_size */