From: Adrian Hunter Date: Thu, 23 Jun 2011 10:40:29 +0000 (+0300) Subject: mmc: queue: bring discard_granularity/alignment into line with SCSI X-Git-Tag: v3.0-rc5~23^2 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=c31b55cd4eaf050bb5a15bd8251da1b3c7edeb1c mmc: queue: bring discard_granularity/alignment into line with SCSI 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 Signed-off-by: Chris Ball --- diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index 3e2db1cf1cbb..6413afa318d2 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -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);