On 17/03/20 3:49 pm, Baolin Wang wrote: > On Tue, Mar 17, 2020 at 9:25 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: >> >> On 17/03/20 12:14 pm, Baolin Wang wrote: >>> This patch set introduces a new request_atomic() interface for the >>> MMC host controller, which is used to submit a request to host in >>> the atomic context, such as in the irq hard handler, to reduce the >>> request latency. >>> >>> Any comments are welcome. Thanks. >>> >>> Note: Adrian pointed out that it is not good if moving the polling of >>> inhibit bits in sdhci_send_command() into the interrupt context, but >>> now I have not found a better way to address Adrian's concern. Moveover >>> this is an unusual abnormal case and the original code has the same >>> problem, so I plan to create another patch set to talk about and fix >>> this issue. >> >> I tend to think the API requires the possibility for host controllers to >> return "busy", so that should be sorted out first. > > If request_atomic() can return 'busy', the HSQ need queue a work to > dispatch this request to host again? Sounds reasonable > > I am thinking if I can introduce a new flag to avoid polling the > status before sending commands, cause from the datasheet, I did not > see we should need do this if the command complete and transfer > complete interrupts are processed normally. At least on my platfrom, I > did not see the inhibit bits are set. If we meet this issue, I think > some abormal things are happened, we should give out errors. How do > you think? For the atomic path, some kind of warning would be ok. > >>> >>> Changes from v1: >>> - Re-split the changes to make them more clear suggested by Ulf. >>> - Factor out the auto CMD23 checking into a separate function. >>> >>> Baolin Wang (3): >>> mmc: host: Introduce the request_atomic() for the host >>> mmc: host: sdhci: Implement the request_atomic() API >>> mmc: host: sdhci-sprd: Implement the request_atomic() API >>> >>> drivers/mmc/host/mmc_hsq.c | 5 ++++- >>> drivers/mmc/host/sdhci-sprd.c | 23 ++++++++++++++++++++--- >>> drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++-------- >>> drivers/mmc/host/sdhci.h | 1 + >>> include/linux/mmc/host.h | 3 +++ >>> 5 files changed, 47 insertions(+), 12 deletions(-) >>> >> > >
