The patch in the following mail is a result of a problem I had using an eMMC device on a Xilinx Zynq ARM processor. It turned out that the waiting for a certain response from the SDIO interface was made with a plain loop, with no absolute time measurement. Since I'm using a relatively fast processor, the timeout expired before the eMMC chip managed to acknowledge an mmc_switch() with EXT_CSD_HS_TIMING.
This patch fixes the problem on my board, and eMMC works properly with it. However I can't say that I really understand what I did, and the 100 ms timeout was chosen with a finger in the wind. If there's a reason why the timeout should be longer or shorter, this is a good time to come forward.
Thanks, Eli
Eli Billauer (1): mmc: sdhci: Fixed timeout for sdhci_send_command()
drivers/mmc/sdhci.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)