On 23/02/21 1:54 pm, Ulf Hansson wrote: > On Tue, 23 Feb 2021 at 12:19, Paul Fertser <fercerpav@xxxxxxxxx> wrote: >> >> Hello Adrian, >> >> On Tue, Feb 23, 2021 at 01:01:09PM +0200, Adrian Hunter wrote: >>> On 23/02/21 11:32 am, Paul Fertser wrote: >>>> Hello Ulf, >>>> >>>> On Tue, Feb 23, 2021 at 10:23:28AM +0100, Ulf Hansson wrote: >>>>>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c >>>>>> index f5dedb7f9b27..9adf735391fa 100644 >>>>>> --- a/drivers/mmc/core/mmc.c >>>>>> +++ b/drivers/mmc/core/mmc.c >>>>>> @@ -426,8 +426,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd) >>>>>> /* EXT_CSD value is in units of 10ms, but we store in ms */ >>>>>> card->ext_csd.part_time = 10 * ext_csd[EXT_CSD_PART_SWITCH_TIME]; >>>>>> /* Some eMMC set the value too low so set a minimum */ >>>>>> - if (card->ext_csd.part_time && >>>>>> - card->ext_csd.part_time < MMC_MIN_PART_SWITCH_TIME) >>>>>> + if (card->ext_csd.part_time < MMC_MIN_PART_SWITCH_TIME) >>>>>> card->ext_csd.part_time = MMC_MIN_PART_SWITCH_TIME; >>>>>> >>>>>> /* Sleep / awake timeout in 100ns units */ >>>>>> >>>>>> I do not see any more warnings on my system. >>>>> >>>>> That looks like the correct fix to the problem. Do you want to send a >>>>> proper patch that I can pick up or do you prefer if help to do it? >>>> >>>> I've sent this as a diff precisely because 1c447116d017 was so >>>> explicit about special-casing zero ext_csd timeout value, so I thought >>>> probably Adrian can provide the rationale for that. I'd prefer to wait >>>> for his feedback before sending a formal patch. Does this make sense? >>> >>> Zero means indefinite. Might be safer to use a higher value than >>> MMC_MIN_PART_SWITCH_TIME for that case. The maximum GENERIC_CMD6_TIME is >>> 2550 ms. >> >> Thanks for the clarification! I would guess that most likely than not >> when whoever defines that value to be zero it means "I do not >> care/know" rather than "the timeout must be set to more than 2550 ms, >> too bad 8 bits are not enough to represent that". I'd say setting it >> to DEFAULT_CMD6_TIMEOUT_MS should be safe enough since it worked >> before. > > Hmm. > > The DEFAULT_CMD6_TIMEOUT_MS is intended to override the > ext_csd->generic_cmd6_time, in case it's not defined in the register. > > Perhaps it's reasonable to think that eMMC vendors specify the > GENERIC_CMD6_TIME, but may skip to specify other timeouts, like the > PARTITION_SWITCH_TIME. In that case, should we use the specified > GENERIC_CMD6_TIME, rather than always default to > DEFAULT_CMD6_TIMEOUT_MS? Sounds reasonable, but perhaps still enforce a minimum, for some of the same reasons as commit 1c447116d017 ? e.g. if (!card->ext_csd.part_time) card->ext_csd.part_time = card->ext_csd.generic_cmd6_time; if (card->ext_csd.part_time < MMC_MIN_PART_SWITCH_TIME) card->ext_csd.part_time = MMC_MIN_PART_SWITCH_TIME;
