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FROMGIT: scsi: ufs: core: Enable DMA clustering

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All UFS host controllers support DMA clustering. Hence enable DMA
clustering.

Notes:

 - The max_segment_size parameter implements the 256 KiB limit for the
   PRDT. The dma_boundary parameter represents a boundary that must not be
   crossed by DMA scatter/gather lists. I'm not aware of any restrictions
   on DMA scatter/gather lists in the UFSHCI specification other than the
   256 KiB limit for the PRDT and the 32-bit address restriction for
   controllers that only support 32-bits DMA. The latter restriction is
   already handled by ufshcd_set_dma_mask().

 - Without patch "scsi: ufs: exynos: Fix the maximum segment size", this
   patch breaks support for the Exynos controller.

The history of the dma_boundary parameter in the UFS driver is as
follows:

 * The initial UFS driver did not set the dma_boundary parameter.

 * Commit 4dd4130a72 ("scsi: make sure all drivers set the use_clustering
   flag") set the .use_clustering flag.

 * Commit 4af14d113b ("scsi: remove the use_clustering flag") removed the
   use_clustering flag and set the dma_boundary parameter instead.

Cc: Avri Altman <avri.altman@wdc.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Kiwoong Kim <kwmad.kim@samsung.com>
Change-Id: I7a14065dee3278b93f51e66b132dd2ffbc3020c4
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 13f87983fb91454e4a534bb41b5b2b43afe97798 git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next)
Signed-off-by: Bart Van Assche <bvanassche@google.com>
This commit is contained in:
Bart Van Assche
2023-01-12 15:42:15 -08:00
committed by Bart Van Assche
parent 1810e7b451
commit c4e9d151d5
1 changed files with 0 additions and 1 deletions
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1
drivers/ufs/core/ufshcd.c
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@@ -8802,7 +8802,6 @@ static struct scsi_host_template ufshcd_driver_template = {
.max_host_blocked = 1, .max_host_blocked = 1,
.track_queue_depth = 1, .track_queue_depth = 1,
.sdev_groups = ufshcd_driver_groups, .sdev_groups = ufshcd_driver_groups,
.dma_boundary = PAGE_SIZE - 1,
.rpm_autosuspend_delay = RPM_AUTOSUSPEND_DELAY_MS, .rpm_autosuspend_delay = RPM_AUTOSUSPEND_DELAY_MS,
}; };