From mboxrd@z Thu Jan 1 00:00:00 1970 From: roger.quadros@nokia.com (Roger Quadros) Date: Tue, 06 Jul 2010 14:02:15 +0300 Subject: [PATCH 05/15] omap: hsmmc: add virtual card detect support In-Reply-To: References: <1278376666-3509-1-git-send-email-ohad@wizery.com> <1278376666-3509-6-git-send-email-ohad@wizery.com> Message-ID: <4C330D37.4090104@nokia.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/06/2010 01:22 PM, ext Ohad Ben-Cohen wrote: > Hi Nicolas, > > On Tue, Jul 6, 2010 at 4:45 AM, Nicolas Pitre wrote: >> On Tue, 6 Jul 2010, Ohad Ben-Cohen wrote: >> >>> From: Ohad Ben-Cohen >>> >>> Add support for software emulation of card detect >>> events. >>> >>> This is required for specific controllers >>> that are hard wired with embedded SDIO devices >>> (such as TI's wl1271 WLAN device). >> >> Why? >> >> Many instances of hardwired SDIO based WLAN devices do exist already, >> and they don't need extra card detect events to be generated. The core >> MMC code already triggers a probe for cards whenever a new host >> controller is registered. > > We prefer not to power up the chip as early as boot time; instead, we Why? if the card is hard wired with no card detect then it should be powered up. The function driver should power it down later if required. no? > would like to have it powered off until the wlan interface is brought > up, power it on when the interface is brought up, If it was powered OFF then how did the wlan interface come into picture? > and power it off again as soon as the interface is brought down again > (to minimize power consumption when the wlan is not in use). I agree, we some how need to power down the card when not in use in the right way.