| Message ID | 54f75bccac6e6e49d87a5122ea670038b508b33c.1465808036.git.baolin.wang@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 19 July 2016 at 19:57, Ulf Hansson <ulf.hansson@linaro.org> wrote: > On 13 June 2016 at 10:54, Baolin Wang <baolin.wang@linaro.org> wrote: >> When mmc host HW supports busy signalling (using R1B as response), We >> shouldn't use 'host->max_busy_timeout' as the limitation when deciding >> the max discard sectors that we tell the generic BLOCK layer about. >> Instead, we should pick one preferred erase size as the max discard >> sectors. >> >> If the host controller supports busy signalling and the timeout for >> the erase operation does not exceed the max_busy_timeout, we should >> use R1B response. Or we need to prevent the host from doing hw busy >> detection, which is done by converting to a R1 response instead. >> >> Changes since v1: >> - Remove the 'MMC_CAP_WAIT_WHILE_BUSY' flag checking when deciding >> the max discard sectors. >> >> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> >> --- >> drivers/mmc/core/core.c | 47 +++++++++++++++++++++++++++++++++++++++-------- >> 1 file changed, 39 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c >> index 8b4dfd4..edd43b1 100644 >> --- a/drivers/mmc/core/core.c >> +++ b/drivers/mmc/core/core.c >> @@ -2060,7 +2060,7 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from, >> unsigned int to, unsigned int arg) >> { >> struct mmc_command cmd = {0}; >> - unsigned int qty = 0; >> + unsigned int qty = 0, busy_timeout = 0; >> unsigned long timeout; >> int err; >> >> @@ -2128,8 +2128,23 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from, >> memset(&cmd, 0, sizeof(struct mmc_command)); >> cmd.opcode = MMC_ERASE; >> cmd.arg = arg; >> - cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; >> - cmd.busy_timeout = mmc_erase_timeout(card, arg, qty); >> + busy_timeout = mmc_erase_timeout(card, arg, qty); >> + /* >> + * If the host controller supports busy signalling and the timeout for >> + * the erase operation does not exceed the max_busy_timeout, we should >> + * use R1B response. Or we need to prevent the host from doing hw busy >> + * detection, which is done by converting to a R1 response instead. >> + */ >> + if ((card->host->max_busy_timeout && >> + busy_timeout > card->host->max_busy_timeout) || >> + !(card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)) { > > sdhci uses the max_busy_timeout, but doesn't always use MMC_CAP_WAIT_WHILE_BUSY. > I have probably asked Adrian about this before, but right now I can't > recall why this is the case. > > Anyway, I don't think we need to check MMC_CAP_WAIT_WHILE_BUSY at this point. Make sense. > >> + cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC; >> + cmd.busy_timeout = 0; >> + } else { >> + cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; >> + cmd.busy_timeout = busy_timeout; >> + } >> + >> err = mmc_wait_for_cmd(card->host, &cmd, 0); >> if (err) { >> pr_err("mmc_erase: erase error %d, status %#x\n", > > You also need to fix the loop for polling with CMD13 to get the card > status. In case of when R1B+MMC_CAP_WAIT_WHILE_BUSY is used, the > polling shall be avoided. Make sense. > > Moreover, the polling loop doesn't care about the earlier used > calculated erase timeout, but instead defaults to the > MMC_CORE_TIMEOUT_MS, this is wrong. Then we should use the earlier calculated erase timeout as the polling time, right? > > Finally, perhaps as an improvement step; I think we shall make use of > the host's ->card_busy() callback if implemented and when > R1B+MMC_CAP_WAIT_WHILE_BUSY isn't used. This in favour of issuing > CMD13 in the loop. > > You can see the sequence in __mmc_switch(), we should apply this to > the erase case as well. Perhaps we can even split up some of the code > in __mmc_switch() to allow it to re-used for the erase case as well!? Make sense. > >> @@ -2321,23 +2336,39 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card, >> unsigned int arg) >> { >> struct mmc_host *host = card->host; >> - unsigned int max_discard, x, y, qty = 0, max_qty, timeout; >> + unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout; >> unsigned int last_timeout = 0; >> >> - if (card->erase_shift) >> + if (card->erase_shift) { >> max_qty = UINT_MAX >> card->erase_shift; >> - else if (mmc_card_sd(card)) >> + min_qty = card->pref_erase >> card->erase_shift; >> + } else if (mmc_card_sd(card)) { >> max_qty = UINT_MAX; >> - else >> + min_qty = card->pref_erase; >> + } else { >> max_qty = UINT_MAX / card->erase_size; >> + min_qty = card->pref_erase / card->erase_size; >> + } >> >> /* Find the largest qty with an OK timeout */ > > This comment needs to be updated. OK. > >> do { >> y = 0; >> for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) { >> timeout = mmc_erase_timeout(card, arg, qty + x); >> - if (timeout > host->max_busy_timeout) >> + /* >> + * We should not only use 'host->max_busy_timeout' as >> + * the limitation when deciding the max discard sectors. >> + * We should set a balance value to improve the erase >> + * speed, and it can not get too long timeout at the >> + * same time. > > I am not really sure I understand this comment. Could you try to > elaborate on what value that will be picked when the max_busy_timeout > isn't just as the limiter. It means we can get the value at least is 'min_qty' no matter what size of max_busy_timeout. But if the max_busy_timeout is large enough for 'min_qty' size, then we can continue to increase the max discard sectors. > >> + * >> + * Here we set 'card->pref_erase' as the minimal discard >> + * sectors when deciding the max discard sectors. >> + */ >> + if (qty + x > min_qty && >> + timeout > host->max_busy_timeout) >> break; >> + >> if (timeout < last_timeout) >> break; >> last_timeout = timeout; >> -- >> 1.7.9.5 >> > > Again, sorry for the delay in response! It's okay:). Thanks for your comments. -- Baolin.wang Best Regards
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 8b4dfd4..edd43b1 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2060,7 +2060,7 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from, unsigned int to, unsigned int arg) { struct mmc_command cmd = {0}; - unsigned int qty = 0; + unsigned int qty = 0, busy_timeout = 0; unsigned long timeout; int err; @@ -2128,8 +2128,23 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from, memset(&cmd, 0, sizeof(struct mmc_command)); cmd.opcode = MMC_ERASE; cmd.arg = arg; - cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; - cmd.busy_timeout = mmc_erase_timeout(card, arg, qty); + busy_timeout = mmc_erase_timeout(card, arg, qty); + /* + * If the host controller supports busy signalling and the timeout for + * the erase operation does not exceed the max_busy_timeout, we should + * use R1B response. Or we need to prevent the host from doing hw busy + * detection, which is done by converting to a R1 response instead. + */ + if ((card->host->max_busy_timeout && + busy_timeout > card->host->max_busy_timeout) || + !(card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)) { + cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC; + cmd.busy_timeout = 0; + } else { + cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; + cmd.busy_timeout = busy_timeout; + } + err = mmc_wait_for_cmd(card->host, &cmd, 0); if (err) { pr_err("mmc_erase: erase error %d, status %#x\n", @@ -2321,23 +2336,39 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card, unsigned int arg) { struct mmc_host *host = card->host; - unsigned int max_discard, x, y, qty = 0, max_qty, timeout; + unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout; unsigned int last_timeout = 0; - if (card->erase_shift) + if (card->erase_shift) { max_qty = UINT_MAX >> card->erase_shift; - else if (mmc_card_sd(card)) + min_qty = card->pref_erase >> card->erase_shift; + } else if (mmc_card_sd(card)) { max_qty = UINT_MAX; - else + min_qty = card->pref_erase; + } else { max_qty = UINT_MAX / card->erase_size; + min_qty = card->pref_erase / card->erase_size; + } /* Find the largest qty with an OK timeout */ do { y = 0; for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) { timeout = mmc_erase_timeout(card, arg, qty + x); - if (timeout > host->max_busy_timeout) + /* + * We should not only use 'host->max_busy_timeout' as + * the limitation when deciding the max discard sectors. + * We should set a balance value to improve the erase + * speed, and it can not get too long timeout at the + * same time. + * + * Here we set 'card->pref_erase' as the minimal discard + * sectors when deciding the max discard sectors. + */ + if (qty + x > min_qty && + timeout > host->max_busy_timeout) break; + if (timeout < last_timeout) break; last_timeout = timeout;
When mmc host HW supports busy signalling (using R1B as response), We shouldn't use 'host->max_busy_timeout' as the limitation when deciding the max discard sectors that we tell the generic BLOCK layer about. Instead, we should pick one preferred erase size as the max discard sectors. If the host controller supports busy signalling and the timeout for the erase operation does not exceed the max_busy_timeout, we should use R1B response. Or we need to prevent the host from doing hw busy detection, which is done by converting to a R1 response instead. Changes since v1: - Remove the 'MMC_CAP_WAIT_WHILE_BUSY' flag checking when deciding the max discard sectors. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> --- drivers/mmc/core/core.c | 47 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 39 insertions(+), 8 deletions(-) -- 1.7.9.5