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| author | Linus Walleij <linus.walleij@linaro.org> | 2024-01-25 09:50:23 +0100 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2024-02-13 13:37:28 +0100 |
| commit | 069279d6fef57b06d5489d6aa8775630903c0da2 (patch) | |
| tree | 97a3b1ce4c62f6112c412ab0f5b3ae0fffc35de4 /drivers/mmc | |
| parent | c64ec3a7d9e93e2e0e06bdc4b1ce760b54676c97 (diff) | |
| download | linux-stable-069279d6fef57b06d5489d6aa8775630903c0da2.tar.gz linux-stable-069279d6fef57b06d5489d6aa8775630903c0da2.tar.bz2 linux-stable-069279d6fef57b06d5489d6aa8775630903c0da2.zip | |
mmc: core Drop BLK_BOUNCE_HIGH
The MMC core sets BLK_BOUNCE_HIGH for devices where dma_mask
is unassigned.
For the majority of MMC hosts this path is never taken: the
OF core will unconditionally assign a 32-bit mask to any
OF device, and most MMC hosts are probed from device tree,
see drivers/of/platform.c:
of_platform_device_create_pdata()
dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
if (!dev->dev.dma_mask)
dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
of_amba_device_create()
dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
MMC devices that are probed from ACPI or PCI will likewise
have a proper dma_mask assigned.
The only remaining devices that could have a blank dma_mask
are platform devices instantiated from board files.
These are mostly used on systems without CONFIG_HIGHMEM
enabled which means the block layer will not bounce, and in
the few cases where it is enabled it is not used anyway:
for example some OMAP2 systems such as Nokia n800/n810 will
create a platform_device and not assign a dma_mask, however
they do not have any highmem, so no bouncing will happen
anyway: the block core checks if max_low_pfn >= max_pfn
and this will always be false.
Should it turn out there is a platform_device with blank
DMA mask actually using CONFIG_HIGHMEM somewhere out there
we should set dma_mask for it, not do this trickery.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240125-mmc-no-blk-bounce-high-v1-1-d0f92a30e085@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/queue.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index a0a2412f62a7..316415588a77 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -351,8 +351,6 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) if (mmc_can_erase(card)) mmc_queue_setup_discard(mq->queue, card); - if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask) - blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH); blk_queue_max_hw_sectors(mq->queue, min(host->max_blk_count, host->max_req_size / 512)); if (host->can_dma_map_merge) |