linux/drivers/mmc/core, branch v4.9

mmc: mmc: Use 500ms as the default generic CMD6 timeout

2016-11-07T12:29:52Z

In the eMMC 4.51 version of the spec, an EXT_CSD field called GENERIC_CMD6_TIME[248] was added. This allows cards to specify the maximum time it may need to move out from its busy state, when a CMD6 command has been sent. In cases when the card is compliant to versions < 4.51 of the eMMC spec, obviously the core needs to use a fall-back value for this timeout, which currently is set to 10 minutes. This value is completely in the wrong range and importantly in some cases it causes a card initialization to take more than 10 minute to complete. Earlier this scenario was avoided as the mmc core used CMD13 to poll the card, to find out when it stopped signaling busy. Commit 08573eaf1a70 ("mmc: mmc: do not use CMD13 to get status after speed mode switch") changed this behavior. Instead of reverting that commit, which would cause other issues, let's instead start by picking a simple solution for the problem, by using a 500ms default generic CMD6 timeout. The reason for using exactly 500ms, comes from observations that shows it's quite common for cards to specify 250ms. 500ms is two times that value so likely it should be enough for most cards. Cc: # v4.8+ Fixes: 08573eaf1a70 ("mmc: mmc: do not use CMD13 to get status after speed mode switch") Signed-off-by: Ulf Hansson Tested-by: Stephen Boyd Tested-by: Linus Walleij

mmc: core: changes frequency to hs_max_dtr when selecting hs400es

2016-10-10T12:01:15Z

Per JESD84-B51 P49, Host need to change frequency to <=52MHz after setting HS_TIMING to 0x1, and host may changes frequency to <= 200MHz after setting HS_TIMING to 0x3. That means the card expects the clock rate to increase from the current used f_init (which is less than 400KHz, but still being less than 52MHz) to 52MHz, otherwise we find some eMMC devices significantly report failure when sending status. Reported-by: Xiao Yao Signed-off-by: Shawn Lin Reviewed-by: Douglas Anderson Signed-off-by: Ulf Hansson

mmc: core: switch to 1V8 or 1V2 for hs400es mode

2016-10-10T12:00:45Z

When introducing hs400es, I didn't notice that we haven't switched voltage to 1V2 or 1V8 for it. That happens to work as the first controller claiming to support hs400es, arasan(5.1), which is designed to only support 1V8. So the voltage is fixed to 1V8. But it actually is wrong, and will not fit for other host controllers. Let's fix it. Fixes: commit 81ac2af65793ecf ("mmc: core: implement enhanced strobe support") Cc: Signed-off-by: Shawn Lin Reviewed-by: Douglas Anderson Signed-off-by: Ulf Hansson

mmc: core: don't try to switch block size for dual rate mode

2016-09-26T19:31:34Z

Per spec, block size should always be 512 bytes for dual rate mode, so any attempts to switch the block size under dual rate mode should be neglected. Signed-off-by: Ziyuan Xu Signed-off-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: core: Add support for sending commands during data transfer

2016-09-26T19:31:28Z

A host controller driver exposes its capability using caps flag MMC_CAP_CMD_DURING_TFR. A driver with that capability can accept requests that are marked mrq->cap_cmd_during_tfr = true. Then the driver informs the upper layers when the command line is available for further commands by calling mmc_command_done(). Because of that, the driver will not then automatically send STOP commands, and it is the responsibility of the upper layer to send a STOP command if it is required. For requests submitted through the mmc_wait_for_req() interface, the caller sets mrq->cap_cmd_during_tfr = true which causes mmc_wait_for_req() in fact not to wait. The caller can then send commands that do not use the data lines. Finally the caller can wait for the transfer to complete by calling mmc_wait_for_req_done() which is now exported. For requests submitted through the mmc_start_req() interface, the caller again sets mrq->cap_cmd_during_tfr = true, but mmc_start_req() anyway does not wait. The caller can then send commands that do not use the data lines. Finally the caller can wait for the transfer to complete in the normal way i.e. calling mmc_start_req() again. Irrespective of how a cap_cmd_during_tfr request is started, mmc_is_req_done() can be called if the upper layer needs to determine if the request is done. However the appropriate waiting function (either mmc_wait_for_req_done() or mmc_start_req()) must still be called. The implementation consists primarily of a new completion mrq->cmd_completion which notifies when the command line is available for further commands. That completion is completed by mmc_command_done(). When there is an ongoing data transfer, calls to mmc_wait_for_req() will automatically wait on that completion, so the caller does not have to do anything special. Note, in the case of errors, the driver may call mmc_request_done() without calling mmc_command_done() because mmc_request_done() always calls mmc_command_done(). Signed-off-by: Adrian Hunter Signed-off-by: Ulf Hansson

mmc: core: Optimize the mmc erase size alignment

2016-09-26T19:31:26Z

In most cases the 'card->erase_size' is power of 2, then the round_up/down() function is more efficient than '%' operation when the 'card->erase_size' is power of 2. Signed-off-by: Baolin Wang Tested-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: core: Factor out the alignment of erase size

2016-09-26T19:31:25Z

In order to clean up the mmc_erase() function and do some optimization for erase size alignment, factor out the guts of erase size alignment into mmc_align_erase_size() function. Signed-off-by: Baolin Wang Tested-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: core: Use a default maximum erase timeout

2016-09-26T19:31:24Z

In cases when the host->max_busy_timeout isn't specified, the calculated number of maximum discard sectors defaults to UINT_MAX. This may cause a too long timeout for a discard request. Avoid this by using a default maximum erase timeout of 60s, used when we calculate the maximum number of sectors that are allowed to be discarded per request. Do note that the minimum number of sectors to be discarded is still at least one "preferred erase size". Signed-off-by: Ulf Hansson Reviewed-by: Shawn Lin

mmc: sdio: deploy error handling instead of triggering BUG_ON

2016-09-26T19:31:15Z

When using mmc_io_rw_extended, it's intent to avoid null pointer of card and invalid func number. But actually it didn't prevent that as the seg_size already use the card. Currently the wrapper function sdio_io_rw_ext_helper already use card before calling mmc_io_rw_extended, so we should move this check to there. As to the func number, it was token from '(ocr & 0x70000000) >> 28' which should be enough to guarantee that it won't be larger than 7. But we should prevent the caller like wifi drivers modify this value. So let's move this check into sdio_io_rw_ext_helper either. Also we remove the BUG_ON for mmc_send_io_op_cond since all possible paths calling this function are protected by checking the arguments in advance. After deploying these changes, we could not see any panic within SDIO API even if func drivers abuse the SDIO func APIs. Signed-off-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: core: Add error message when switching fails in mmc_select_hs()

2016-09-26T19:31:14Z

The switch failure message in mmc_select_timing() had been removed since that is invalid: commit 0400ed0a083a ("mmc: core: remove the invalid message in mmc_select_timing") Now, in the case when mmc_select_hs() return error in mmc_select_timing(), there is nothing to print failure message. Let's make for mmc_select_hs() print message itself in the failure case. Signed-off-by: Jungseung Lee Signed-off-by: Ulf Hansson