Hi Manoj, adding linux-mmc@, On Mon, Jul 11 2011, Manoj Iyer wrote: > Ricoh 1180:e823 does not recognize certain types of SD/MMC cards. > Lowering the SD base clock frequency from 200Mhz to 50Mhz fixes > this issue. This solution was suggest by Koji Matsumuro, Ricoh > Company,Ltd. > > BugLink: http://launchpad.net/bugs/773524 > Signed-off-by: Manoj Iyer <manoj.iyer@xxxxxxxxxxxxx> > Tested-by: Daniel Manrique <daniel.manrique@xxxxxxxxxxxxx> > Cc: Koji Matsumuro <matsumur@xxxxxxxxxxxxxxx> > --- > drivers/pci/quirks.c | 24 ++++++++++++++++++++++++ > 1 files changed, 24 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 02145e9..fe5bffa 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -2758,6 +2758,30 @@ static void ricoh_mmc_fixup_r5c832(struct pci_dev *dev) > > dev_notice(&dev->dev, "proprietary Ricoh MMC controller disabled (via firewire function)\n"); > dev_notice(&dev->dev, "MMC cards are now supported by standard SDHCI controller\n"); > + > + /* > + * RICOH 0xe823 SD/MMC card reader fails to recognize > + * certain types of SD/MMC cards. Lowering the SD base > + * clock frequency from 200Mhz to 50Mhz fixes this issue. > + * > + * 0x150 - SD2.0 mode enable for changing base clock > + * frequency to 50Mhz > + * 0xe1 - Base clock frequency > + * 0x32 - 50Mhz new clock frequency > + * 0xf9 - Key register for 0x150 > + * 0xfc - key register for 0xe1 > + */ > + if (dev->device == PCI_DEVICE_ID_RICOH_R5CE823) { > + pci_write_config_byte(dev, 0xf9, 0xfc); > + pci_write_config_byte(dev, 0x150, 0x10); > + pci_write_config_byte(dev, 0xf9, 0x00); > + pci_write_config_byte(dev, 0xfc, 0x01); > + pci_write_config_byte(dev, 0xe1, 0x32); > + pci_write_config_byte(dev, 0xfc, 0x00); > + > + dev_notice(&dev->dev, "Controller base frequency changed to 50Mhz)\n"); There's an erroneous ")" in this string; I'll replace it with a "." if this patch goes in via my tree. Also, let's make it "MMC controller" instead of just "Controller". > + } > + > } > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832); > DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832); Have you checked to see how SD I/O performance differs after this change? (If this is significant, perhaps we want to try lowering the frequency only after a card starts returning errors, since some cards work fine at the higher frequency.) Thanks, - Chris. -- Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
