> -----Original Message----- > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > owner@xxxxxxxxxxxxxxx] On Behalf Of Nath, Arindam > Sent: Wednesday, March 09, 2011 8:01 PM > To: subhashj@xxxxxxxxxxxxxx; cjb@xxxxxxxxxx > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; linux- > mmc@xxxxxxxxxxxxxxx; Su, Henry; Lu, Aaron; anath.amd@xxxxxxxxx > Subject: RE: [PATCH v2 03/12] mmc: sd: query function modes for uhs > cards > > Hi Subhash, > > > > -----Original Message----- > > From: subhashj@xxxxxxxxxxxxxx [mailto:subhashj@xxxxxxxxxxxxxx] > > Sent: Wednesday, March 09, 2011 7:39 PM > > To: Nath, Arindam; cjb@xxxxxxxxxx > > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; linux- > > mmc@xxxxxxxxxxxxxxx; Su, Henry; Lu, Aaron; anath.amd@xxxxxxxxx > > Subject: RE: [PATCH v2 03/12] mmc: sd: query function modes for uhs > > cards > > > > > > > > > -----Original Message----- > > > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Arindam Nath > > > Sent: Friday, March 04, 2011 5:03 PM > > > To: cjb@xxxxxxxxxx > > > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; > > > subhashj@xxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; > henry.su@xxxxxxx; > > > aaron.lu@xxxxxxx; anath.amd@xxxxxxxxx; Arindam Nath > > > Subject: [PATCH v2 03/12] mmc: sd: query function modes for uhs > cards > > > > > > SD cards which conform to Physical Layer Spec v3.01 can support > > > additional Bus Speed Modes, Driver Strength, and Current Limit > > > other than the default values. We use CMD6 mode 0 to read these > > > additional card functions. The values read here will be used > > > during UHS-I initialization steps. > > > > > > Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx> > > > --- > > > drivers/mmc/core/sd.c | 99 > > > +++++++++++++++++++++++++++++++++++++++------- > > > include/linux/mmc/card.h | 3 + > > > 2 files changed, 87 insertions(+), 15 deletions(-) > > > > > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > > > index 3e82599..a63956b 100644 > > > --- a/drivers/mmc/core/sd.c > > > +++ b/drivers/mmc/core/sd.c > > > @@ -283,25 +283,94 @@ static int mmc_read_switch(struct mmc_card > > *card) > > > return -ENOMEM; > > > } > > > > > > - err = mmc_sd_switch(card, 0, 0, 1, status); > > > - if (err) { > > > - /* If the host or the card can't do the switch, > > > - * fail more gracefully. */ > > > - if ((err != -EINVAL) > > > - && (err != -ENOSYS) > > > - && (err != -EFAULT)) > > > + if (card->scr.sda_spec3) { > > > + /* First find out the supported Bus Speed Modes. */ > > > + err = mmc_sd_switch(card, 0, 0, 1, status); > > Reading function-group-1 status applies for both SD3.0 and SD2.0 > cards > > as > > well. With card->scr.sda_spec check, you are duplicating the same > code > > in > > else part of it as well. You can optimize it to only one call to > > mmc_sd_switch() to read function-group-1. > > Yes, there is a duplication of the code. I will try to minimize it in > the next version. > > > > > > + if (err) { > > > + /* > > > + * If the host or the card can't do the switch, > > > + * fail more gracefully. > > > + */ > > > + if ((err != -EINVAL) > > > + && (err != -ENOSYS) > > > + && (err != -EFAULT)) > > > + goto out; > > > + > > > + printk(KERN_WARNING "%s: problem reading " > > > + "Bus Speed modes.\n", > > > + mmc_hostname(card->host)); > > > + err = 0; > > > + > > > goto out; > > > + } > > > > > > - printk(KER N_WARNING "%s: problem reading switch " > > > - "capabilities, performance might suffer.\n", > > > - mmc_hostname(card->host)); > > > - err = 0; > > > + card->sw_caps.uhs_bus_mode = status[13]; > > Is adding uhs* prefix is appropriate? If card supports SD3.0 spec > means > > card > > have to support UHS modes? Can we have cards (SDXC?) which sets SD3.0 > > spec > > bit in SCR but does not support any of the UHS modes. So in this case > > putting uhs* prefix might not be appropriate. > > As per Physical Layer Spec v3.01, UHS-I can be applied to SDHC and SDXC > cards. Cards which support UHS-I should have sda_spec3 set in the SCR > register. Since we need to set the data rate depending on the exact > UHS-I speed mode, I have prefixed the variable with uhs_ to make things > clear. UHS-I speed mode support is not a must condition to set SD_SPEC3 bit to 1 in SCR register: This is what the spec says: . Essential conditions to indicate Version 3.00 Card (SD_SPEC=2 and SD_SPEC3=1) (1) The card shall support CMD6 (2) The card shall support CMD8 (3) The card shall support CMD42 (4) User area capacity shall be up to 2GB (SDSC) or 32GB (SDHC) User area capacity shall be more than or equal to 32GB and up to 2TB (SDXC) (5) Speed Class shall be supported (SDHC or SDXC) Supporting UHS-I mode is an optional conditional. > > Thanks, > Arindam > > > > > > > > + > > > + /* Find out Driver Strengths supported by the card */ > > > + err = mmc_sd_switch(card, 0, 2, 1, status); > > > + if (err) { > > > + /* > > > + * If the host or the card can't do the switch, > > > + * fail more gracefully. > > > + */ > > > + if ((err != -EINVAL) > > > + && (err != -ENOSYS) > > > + && (err != -EFAULT)) > > > + goto out; > > > + > > > + printk(KERN_WARNING "%s: problem reading " > > > + "Driver Strength.\n", > > > + mmc_hostname(card->host)); > > > + err = 0; > > > > > > - goto out; > > > - } > > > + goto out; > > > + } > > > > > > - if (status[13] & 0x02) > > > - card->sw_caps.hs_max_dtr = 50000000; > > > + card->sw_caps.uhs_drv_type = status[9]; > > > + > > > + /* Find out Current Limits supported by the card */ > > > + err = mmc_sd_switch(card, 0, 3, 1, status); > > > + if (err) { > > > + /* > > > + * If the host or the card can't do the switch, > > > + * fail more gracefully. > > > + */ > > > + if ((err != -EINVAL) > > > + && (err != -ENOSYS) > > > + && (err != -EFAULT)) > > > + goto out; > > > + > > > + printk(KERN_WARNING "%s: problem reading " > > > + "Current Limit.\n", > > > + mmc_hostname(card->host)); > > > + err = 0; > > > + > > > + goto out; > > > + } > > > + > > > + card->sw_caps.uhs_curr_limit = status[7]; > > > + } else { > > > + err = mmc_sd_switch(card, 0, 0, 1, status); > > > + if (err) { > > > + /* > > > + * If the host or the card can't do the switch, > > > + * fail more gracefully. > > > + */ > > > + if ((err != -EINVAL) > > > + && (err != -ENOSYS) > > > + && (err != -EFAULT)) > > > + goto out; > > > + > > > + printk(KERN_WARNING "%s: problem reading switch " > > > + "capabilities, performance might suffer.\n", > > > + mmc_hostname(card->host)); > > > + err = 0; > > > + goto out; > > > + } > > > + > > > + if (status[13] & 0x02) > > > + card->sw_caps.hs_max_dtr = 50000000; > > > + } > > > > > > out: > > > kfree(status); > > > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > > > index 22b0335..7080f22 100644 > > > --- a/include/linux/mmc/card.h > > > +++ b/include/linux/mmc/card.h > > > @@ -75,6 +75,9 @@ struct sd_ssr { > > > > > > struct sd_switch_caps { > > > unsigned int hs_max_dtr; > > > + unsigned int uhs_bus_mode; > > > + unsigned int uhs_drv_type; > > > + unsigned int uhs_curr_limit; > > > }; > > > > > > struct sdio_cccr { > > > -- > > > 1.7.1 > > > > > > -- > > > 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 > > > > > -- > 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 -- 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
