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[0/5] mmc: core: Add support for graceful host removal for eMMC/SD

Message ID 20250320140040.162416-1-ulf.hansson@linaro.org
Headers show
Series mmc: core: Add support for graceful host removal for eMMC/SD | expand

Message

Ulf Hansson March 20, 2025, 2 p.m. UTC 
As pointed out by Wolfram Sang and already discussed at LKML [1] - an mmc host
driver may allow to unbind from its corresponding host device. If there is and
eMMC/SD card attached to the host, the mmc core will just try to cut the power
for it, without trying to make a graceful power-off, thus potentially we could
damage the card.

This series intends to fix this problem for eMMC/SD cards.

Please help to test and review!

Kind regards
Ulf Hansson

[1]
https://lore.kernel.org/all/20241007093447.33084-2-wsa+renesas@sang-engineering.com/

Ulf Hansson (5):
  mmc: core: Convert mmc_can_poweroff_notify() into a bool
  mmc: core: Further avoid re-storing power to the eMMC before a
    shutdown
  mmc: core: Convert into an enum for the poweroff-type for eMMC
  mmc: core: Add support for graceful host removal for eMMC
  mmc: core: Add support for graceful host removal for SD

 drivers/mmc/core/mmc.c | 66 +++++++++++++++++++++++++++++-------------
 drivers/mmc/core/sd.c  | 25 +++++++++-------
 2 files changed, 61 insertions(+), 30 deletions(-)

Comments

Wolfram Sang March 31, 2025, 8:32 a.m. UTC | #1 
> Awesome! Thank you. Will surely check it out. Not before next week I am
> afraid. But already looking forward to testing it!

So, I tested this with a Renesas Spider board (R-Car S4). The three
cases (shutdown, suspend, unbind) all lead to proper flagging if notify
can't be used or not. Only the question from patch 2 is left open.

But thank you, this has come a long way :)