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0a55f4ab96
Normally when the MMC core sees an "-EILSEQ" error returned by a host controller then it will trigger a retuning of the card. This is generally a good idea. However, if a command is expected to sometimes cause transfer errors then these transfer errors shouldn't cause a re-tuning. This re-tuning will be a needless waste of time. One example case where a transfer is expected to cause errors is when transitioning between idle (sometimes referred to as "sleep" in Broadcom code) and active state on certain Broadcom WiFi SDIO cards. Specifically if the card was already transitioning between states when the command was sent it could cause an error on the SDIO bus. Let's add an API that the SDIO function drivers can call that will temporarily disable the auto-tuning functionality. Then we can add a call to this in the Broadcom WiFi driver and any other driver that might have similar needs. NOTE: this makes the assumption that the card is already tuned well enough that it's OK to disable the auto-retuning during one of these error-prone situations. Presumably the driver code performing the error-prone transfer knows how to recover / retry from errors. ...and after we can get back to a state where transfers are no longer error-prone then we can enable the auto-retuning again. If we truly find ourselves in a case where the card needs to be retuned sometimes to handle one of these error-prone transfers then we can always try a few transfers first without auto-retuning and then re-try with auto-retuning if the first few fail. Without this change on rk3288-veyron-minnie I periodically see this in the logs of a machine just sitting there idle: dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ Cc: stable@vger.kernel.org #v4.18+ Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> |
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