[PATCH 4/4] mmc: mmci: Fix incorrect handling of HW flow control for SDIO

Stefan Nilsson XK stefan.xk.nilsson at stericsson.com
Mon Oct 3 03:31:14 EDT 2011


Hi Russel,

On 10/01/2011 06:12 PM, Russell King - ARM Linux wrote:
> Shouldn't this also re-enable the ST hardware flow control for non-SDIO
> cards?

I do not think that is needed. Hardware flow control is turned on per 
default for all cards thanks to the .clkreg member of the variant struct:

	mmci_set_clkreg():
		clk |= variant->clkreg_enable;
where
	static struct variant_data variant_ux500v2 = {
		.clkreg_enable          = MCI_ST_UX500_HWFCEN,

This means that HWFC will be on for all cards. This patch only disables 
it for SDIO cards (thanks to the mmc_card_sdio()-check) during 
problematic transfers (HW peculiarity), and then re-enables it again for 
SDIO cards during "normal" transfers. So the HWFC state for non-SDIO 
cards should not be touched I think.

Best Regards

Stefan Nilsson



More information about the linux-arm-kernel mailing list