mmc: dw_mmc: return -EILSEQ for EBE and SBE error
The following log we found indicate the fact that dw_mmc didn't treat EBE or SBE as a similar problem as CRC error. -EIO is quite not informative as it may indicate that the device is broken rather than that of tuning stuff. ... [ 89.057226] bcmsdh_sdmmc: Failed to Read byte F1:@0x1001f=ff, Err: -5 [ 89.058811] bcmsdh_sdmmc: Failed to Read byte F1:@0x1001f=ff, Err: -5 [ 89.059415] bcmsdh_sdmmc: Failed to Read byte F1:@0x1000e=ff, Err: -84 [ 89.254248] dwmmc_rockchip fe310000.dwmmc: Successfully tuned phase to 199 [ 89.273912] dhd_set_suspend: Remove extra suspend setting [ 89.274478] dhd_enable_packet_filter: enter, value = 0 64 bytes from 112.90.83.112: icmp_seq=24 ttl=53 time=1321 ms 64 bytes from 112.90.83.112: icmp_seq=25 ttl=53 time=319 ms 64 bytes from 112.90.83.112: icmp_seq=26 ttl=53 time=69.8 ms 64 bytes from 112.90.83.112: icmp_seq=27 ttl=53 time=37.5 ms ... For the host, when failing to sample cmd's response due to tuning stuff, we still return -EIO as it's quite vague to figure out whether it related to signal or just the broken devices, especially for the card type detection when booting kernel as all things go well but the cmd set used. But for the data phase, if receiving the cmd's response which carriess data transfer, we should have more confidence that it is very probably related to the tuning stuff. Just as the log shown above, we sometimes suffer too much this kind of pain as the dw_mmc return -EIO for the case, so mmc-core will not do retune and caller drivers like bcm's wifi driver, still retry the failure more and more until dw_mmc finally generate CRC. Adrian suggested that drivers who care the specific cases should call mmc_retune_needed rather than doing it in mmc core. It makes sense but I'm considering that -EILSEQ actually means illegal sequence , so we use it for CRC cases. Meanwhile, SBE/EBE indicate the illegal sequence of start bit or end bit for data0~7. So I realize that we should use -EILSEQ for them both as well CRC cases. Suggested-by:Adrian Hunter <adrian.hunter@intel.com> Signed-off-by:
Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by:
Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by:
Ulf Hansson <ulf.hansson@linaro.org>
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