So, I had a need to use my SDHC card in my Dell Studio 17 (1737) notebook. So, I set out to find out why it wasn't working. I ended up finding out that I needed to load mmc_block and sdhci-pci in order to get it to work. Here's what I did.
I happen to be using kernel 2.6.30, so your configuration may vary.
<M> MMC/SD/SDIO card support ---> <M> MMC block device driver [*] Use bounce buffer for simple hosts <M> SDIO UART/GPS class support <M> Secure Digital Host Controller Interface support <M> SDHCI support on PCI bus
Gentoo Module Loading
Add the mmc_block and sdhci-pci modules to the configuration at /etc/modules.autoload.d/kernel-2.6
Then I just loaded them by issuing...
modprobe mmc_block modprobe sdhci-pci
For those searching on the internet, who might have the same MMC/SD chipsets as me.
tdamac linux # lspci -vvnn | grep Ricoh 09:01.0 FireWire (IEEE 1394) [0c00]: Ricoh Co Ltd R5C832 IEEE 1394 Controller [1180:0832] (rev 05) (prog-if 10 [OHCI]) 09:01.1 SD Host controller : Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter [1180:0822] (rev 22) (prog-if 01) 09:01.2 System peripheral : Ricoh Co Ltd R5C843 MMC Host Controller [1180:0843] (rev 12) 09:01.3 System peripheral : Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter [1180:0592] (rev 12) 09:01.4 System peripheral : Ricoh Co Ltd xD-Picture Card Controller [1180:0852] (rev ff) (prog-if ff)