mmc: queue: bring discard_granularity/alignment into line with SCSI (c31b55cd) · Commits · 戴 / test

SCSI defines discard alignment as the offset to the first optimal discard. In the case of SD/MMC, that is always zero which is the default. SCSI defines discard granularity as a hint of a optimal discard size. That is much better expressed by the MMC "preferred erase size" (pref_erase) field. Signed-off-by:

Adrian Hunter <adrian.hunter@intel.com> Signed-off-by:

Chris Ball <cjb@laptop.org>

drivers/mmc/card/queue.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -135,12 +135,7 @@ int mmc_init_queue(struct mmc_queue mq, struct mmc_card card,
		mq->queue->limits.max_discard_sectors = UINT_MAX;
		if (card->erased_byte == 0)
		mq->queue->limits.discard_zeroes_data = 1;
		if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) {
		mq->queue->limits.discard_granularity =
		card->erase_size << 9;
		mq->queue->limits.discard_alignment =
		card->erase_size << 9;
		}
		mq->queue->limits.discard_granularity = card->pref_erase << 9;
		if (mmc_can_secure_erase_trim(card))
		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD,
		mq->queue);

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