On Thu, Mar 24, 2016 at 09:06:45AM -0700, Doug Anderson wrote: > Russell, ... > Presumably this is similar to what you saw: the host saw the CRC error > but the card knew nothing about it. Sending the stop command during > this time confused the card. Presumably the card was in transfer > state during this time? If the card was in transfer state for a command which expects a stop command, and that stop command was issued after the card entered the transfer state, then I'd expect the card to handle it... though there's always the firmware bug issue. If the card hadn't entered transfer state at the time the stop command was issued.. I think that's more likely to hit card firmware issues. With the tuning commands, there's another case you can hit though: the data transfer may have completed before you get around to sending the stop command. That's why, for sdhci, I came to the conclusion that waiting for the data transfer to complete or timeout was the best solution for SDHCI. Maybe, if sending a STOP command does cause card firmware issues, then: 1) it provides evidence that trying to send a stop command on response CRC error is the wrong thing to do (it was talked about making SDHCI do this.) 2) it suggests that the solution I came up with for SDHCI is the better solution, rather than trying to immediately recover the situation by sending a STOP command. Maybe dw-mmc can do something similar, but with the lack of data transfer timeout, maybe it's possible to do something with a kernel timer instead, and check what the hardware is doing after a response CRC error? -- RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
