Thanks for the comment. Yes, I actually have the same question. The change here is to fix a condition based on the existing code. Probably a better fix is to get rid of the 'connection'... -----Original Message----- From: Alex Lemberg <Alex.Lemberg@xxxxxxx> Sent: Tuesday, December 4, 2018 11:27 AM To: Liming Sun <lsun@xxxxxxxxxxxx>; Ulf Hansson <ulf.hansson@xxxxxxxxxx>; Jaehoon Chung <jh80.chung@xxxxxxxxxxx>; David Woods <dwoods@xxxxxxxxxxxx>; Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> Cc: linux-mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx Subject: Re: [PATCH v1 1/1] mmc: core: control EXT_CSD_CACHE_CTRL from device tree Hi, On 11/20/18, 10:07 PM, "linux-mmc-owner@xxxxxxxxxxxxxxx on behalf of Liming Sun" <linux-mmc-owner@xxxxxxxxxxxxxxx on behalf of lsun@xxxxxxxxxxxx> wrote: Currently the EXT_CSD_CACHE_CTRL register is controlled by API mmc_card_broken_hpi(), which only works for the quirks settings. This commit enhances it to use card->ext_csd.hpi instead. This flag works for both the quirks and the broken-hpi configuration in the device tree. Signed-off-by: Liming Sun <lsun@xxxxxxxxxxxx> --- drivers/mmc/core/mmc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index bc1bd2c..2f2b65c 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1791,8 +1791,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, * If cache size is higher than 0, this indicates * the existence of cache and it can be turned on. */ - if (!mmc_card_broken_hpi(card) && - card->ext_csd.cache_size > 0) { + if (card->ext_csd.hpi && card->ext_csd.cache_size > 0) { Any reason for making a connection between HPI and Cache in current driver implementation? BTW, I missed it before, but the previous commit making this connection - is also doesn't make any sense. Although by the spec FLUSH_CACHE is interruptible command, I don't think we should prevent devices with no HPI support, using the Cache. Please correct me if I wrong, but the current driver implementation allows to send HPI for BKOPS and Sanitize (on timeout error) commands only - so why we should limit the FLUSH_CACHE command? err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_CACHE_CTRL, 1, card->ext_csd.generic_cmd6_time); -- 1.8.3.1