Dear Pantelis,
On 09/09/2013 02:58 PM, Przemyslaw Marczak wrote:
According to JEDEC eMMC specification, after data transfer (multiple or single block) host must wait for card ready status. This is done by waiting for command and data lines to be at idle state after transfer. JEDEC does not specify maximum timeout.
Before this change max timeout was 10 ms but in case of UMS
- when system does multiple read/write operations on random
card blocks - timeout causes I/O errors. The timeout has been increased to 200ms after data transfer. For other transfers it stays unchanged. Default values are now defined with "if defined" directive so it can be redefined at board config if needed.
Tested on Goni and Trats.
Signed-off-by: Przemyslaw Marczak p.marczak@samsung.com Cc: Pantelis Antoniou panto@antoniou-consulting.com
Please do not apply this patch yet due to still not enough results on some targets. Timeout value should depends on internal cards operations execution time but this time is unpredictably and that is why JEDEC not specifies it. Maybe u-boot sdhci driver needs some more changes to be more flexible for such operations. In example sdhci background operations timeout at kernel is specified to 4 minutes. I need to make more research.
Regards,