| Message ID | 1448462391-22480-1-git-send-email-carlo@caione.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 25 November 2015 at 15:39, Carlo Caione <carlo@caione.org> wrote: > From: Carlo Caione <carlo@endlessm.com> > > This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc > core to not send SDIO specific commands. I guess there are two reasons to why such capability is useful. 1) The host controller/driver doesn't support SDIO. 2) There is an embedded/non-removable eMMC/SD card. Within that context, we might also want to add MMC_CAP2_NO_MMC|SD, or what do you think? Because of 2), we might also want to add a new mmc DT binding or perhaps try interpret a combination of them to enable MMC_CAP2_NO_SDIO!? > > Signed-off-by: Carlo Caione <carlo@endlessm.com> Thanks, applied for next! Kind regards Uffe > --- > > Drivers fix will follow. > > Changelog: > > * v2: > - moved check from __mmc_start_request to mmc_rescan_try_freq > > --- > drivers/mmc/core/core.c | 11 ++++++++--- > include/linux/mmc/host.h | 1 + > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 5ae89e4..8a4e0d2 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2476,15 +2476,20 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq) > * sdio_reset sends CMD52 to reset card. Since we do not know > * if the card is being re-initialized, just send it. CMD52 > * should be ignored by SD/eMMC cards. > + * Skip it if we already know that we do not support SDIO commands > */ > - sdio_reset(host); > + if (!(host->caps2 & MMC_CAP2_NO_SDIO)) > + sdio_reset(host); > + > mmc_go_idle(host); > > mmc_send_if_cond(host, host->ocr_avail); > > /* Order's important: probe SDIO, then SD, then MMC */ > - if (!mmc_attach_sdio(host)) > - return 0; > + if (!(host->caps2 & MMC_CAP2_NO_SDIO)) > + if (!mmc_attach_sdio(host)) > + return 0; > + > if (!mmc_attach_sd(host)) > return 0; > if (!mmc_attach_mmc(host)) > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 8673ffe..cf6d0bb 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -289,6 +289,7 @@ struct mmc_host { > #define MMC_CAP2_HSX00_1_2V (MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V) > #define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17) > #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */ > +#define MMC_CAP2_NO_SDIO (1 << 19) /* Do not send SDIO commands during initialization */ > > mmc_pm_flag_t pm_caps; /* supported pm features */ > > -- > 2.5.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 25, 2015 at 5:34 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote: > On 25 November 2015 at 15:39, Carlo Caione <carlo@caione.org> wrote: >> From: Carlo Caione <carlo@endlessm.com> >> >> This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc >> core to not send SDIO specific commands. > > I guess there are two reasons to why such capability is useful. > 1) The host controller/driver doesn't support SDIO. > 2) There is an embedded/non-removable eMMC/SD card. > > Within that context, we might also want to add MMC_CAP2_NO_MMC|SD, or > what do you think? Is there really any driver / controller not supporting MMC|SD commands? > Because of 2), we might also want to add a new mmc DT binding or > perhaps try interpret a combination of them to enable > MMC_CAP2_NO_SDIO!? Probably I'm missing something but what would be the difference with the 'non-removable' parameter we already have? >> >> Signed-off-by: Carlo Caione <carlo@endlessm.com> > > Thanks, applied for next! Thanks,
On 25 November 2015 at 18:16, Carlo Caione <carlo@endlessm.com> wrote: > On Wed, Nov 25, 2015 at 5:34 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote: >> On 25 November 2015 at 15:39, Carlo Caione <carlo@caione.org> wrote: >>> From: Carlo Caione <carlo@endlessm.com> >>> >>> This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc >>> core to not send SDIO specific commands. >> >> I guess there are two reasons to why such capability is useful. >> 1) The host controller/driver doesn't support SDIO. >> 2) There is an embedded/non-removable eMMC/SD card. >> >> Within that context, we might also want to add MMC_CAP2_NO_MMC|SD, or >> what do you think? > > Is there really any driver / controller not supporting MMC|SD commands? Probably not. I was thinking of optimizing the time it takes to detect a card. For example, if we know it's a non-removable eMMC, we can skip the SDIO and SD part in the initialization sequence. Whether that's really worth to optimize I don't know without measuring the times. [...] Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 5ae89e4..8a4e0d2 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2476,15 +2476,20 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq) * sdio_reset sends CMD52 to reset card. Since we do not know * if the card is being re-initialized, just send it. CMD52 * should be ignored by SD/eMMC cards. + * Skip it if we already know that we do not support SDIO commands */ - sdio_reset(host); + if (!(host->caps2 & MMC_CAP2_NO_SDIO)) + sdio_reset(host); + mmc_go_idle(host); mmc_send_if_cond(host, host->ocr_avail); /* Order's important: probe SDIO, then SD, then MMC */ - if (!mmc_attach_sdio(host)) - return 0; + if (!(host->caps2 & MMC_CAP2_NO_SDIO)) + if (!mmc_attach_sdio(host)) + return 0; + if (!mmc_attach_sd(host)) return 0; if (!mmc_attach_mmc(host)) diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 8673ffe..cf6d0bb 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -289,6 +289,7 @@ struct mmc_host { #define MMC_CAP2_HSX00_1_2V (MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V) #define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17) #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */ +#define MMC_CAP2_NO_SDIO (1 << 19) /* Do not send SDIO commands during initialization */ mmc_pm_flag_t pm_caps; /* supported pm features */