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mmc: meson-gx: check for scatterlist size alignment in block mode

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Enable SGDMA support for SD_IO_RW_EXTENDED and add proper check
for scatterlist size alignment in block mode.

According to documentation, in SDIO block mode meson-gx DMA could
only handle buffers with sizes that are multiples of SDIO block size.

Some SDIO drivers like brcmfmac use scatterlist API, but do not enforce
proper scatterlist buffer size alignemnt, this looks like a root cause
of non-working CMD53.

Some minor style fixes.

Signed-off-by: Dmitry Lebed <lebed.dmitry@gmail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201218075312.67338-1-lebed.dmitry@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Dmitry Lebed 2020-12-17 23:53:12 -08:00 committed by Ulf Hansson
parent 0354ca6edd
commit e085b51c74
1 changed files with 25 additions and 18 deletions
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43
drivers/mmc/host/meson-gx-mmc.c
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@ -227,7 +227,6 @@ static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
struct mmc_data *data = mrq->data; struct mmc_data *data = mrq->data;
struct scatterlist *sg; struct scatterlist *sg;
int i; int i;
bool use_desc_chain_mode = true;
/* /*
* When Controller DMA cannot directly access DDR memory, disable * When Controller DMA cannot directly access DDR memory, disable
@ -237,25 +236,33 @@ static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
if (host->dram_access_quirk) if (host->dram_access_quirk)
return; return;
/* if (data->blocks > 1) {
* Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been /*
* reported. For some strange reason this occurs in descriptor * In block mode DMA descriptor format, "length" field indicates
* chain mode only. So let's fall back to bounce buffer mode * number of blocks and there is no way to pass DMA size that
* for command SD_IO_RW_EXTENDED. * is not multiple of SDIO block size, making it impossible to
*/ * tie more than one memory buffer with single SDIO block.
if (mrq->cmd->opcode == SD_IO_RW_EXTENDED) * Block mode sg buffer size should be aligned with SDIO block
return; * size, otherwise chain mode could not be used.
*/
for_each_sg(data->sg, sg, data->sg_len, i) for_each_sg(data->sg, sg, data->sg_len, i) {
/* check for 8 byte alignment */ if (sg->length % data->blksz) {
if (sg->offset & 7) { WARN_ONCE(1, "unaligned sg len %u blksize %u\n",
WARN_ONCE(1, "unaligned scatterlist buffer\n"); sg->length, data->blksz);
use_desc_chain_mode = false; return;
break; }
} }
}
if (use_desc_chain_mode) for_each_sg(data->sg, sg, data->sg_len, i) {
data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE; /* check for 8 byte alignment */
if (sg->offset % 8) {
WARN_ONCE(1, "unaligned scatterlist buffer\n");
return;
}
}
data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
} }
static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data) static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)