| Message ID | 20090710124054.1262.18902.sendpatchset@ahunter-tower (mailing list archive) |
|---|---|
| State | Awaiting Upstream, archived |
| Headers | show |
On Fri, Jul 10, 2009 at 03:40:54PM +0300, Adrian Hunter wrote: > > Some hosts can accept only certain types of cards. > For example, an eMMC is MMC only and a uSD slot may > be SD only. However the MMC card scanning logic > checks for all card types one by one. > > Add host capabilities to specify which card types > cannot be used, and amend the card scanning logic > to skip scanning for those types. > I'm only nitpicking here, but I think that logic is a little inverted. By saying which cards cannot be used (as opposed to which cards can be used), we get conditionals like this, > > - mmc_send_if_cond(host, host->ocr_avail); > + if (!(host->caps & MMC_CAP_NOT_SDIO) || !(host->caps & MMC_CAP_NOT_SD)) > + mmc_send_if_cond(host, host->ocr_avail); > + Whilst reviewing this patch it took my brain a few too many seconds to parse that as "if the host is capable of SDIO or SD". > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 0a60b02..e996967 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -150,6 +150,13 @@ struct mmc_host { > #define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */ > #define MMC_CAP_NONREMOVABLE (1 << 8) /* Nonremovable e.g. eMMC */ > #define MMC_CAP_WAIT_WHILE_BUSY (1 << 9) /* Waits while card is busy */ > +#define MMC_CAP_NOT_SDIO (1 << 10) /* Card cannot be SDIO */ > +#define MMC_CAP_NOT_SD (1 << 11) /* Card cannot be SD */ > +#define MMC_CAP_NOT_MMC (1 << 12) /* Card cannot be MMC */ > + > +#define MMC_CAP_SDIO_ONLY (MMC_CAP_NOT_SD | MMC_CAP_NOT_MMC) > +#define MMC_CAP_SD_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_MMC) > +#define MMC_CAP_MMC_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_SD) > And by saying what capabilities a host supports, when we add new capabilities we don't have to modify existing code to say that it doesn't support the new capability. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Fleming wrote: > On Fri, Jul 10, 2009 at 03:40:54PM +0300, Adrian Hunter wrote: >> Some hosts can accept only certain types of cards. >> For example, an eMMC is MMC only and a uSD slot may >> be SD only. However the MMC card scanning logic >> checks for all card types one by one. >> >> Add host capabilities to specify which card types >> cannot be used, and amend the card scanning logic >> to skip scanning for those types. >> > > I'm only nitpicking here, but I think that logic is a little inverted. > By saying which cards cannot be used (as opposed to which cards can be > used), we get conditionals like this, > >> >> - mmc_send_if_cond(host, host->ocr_avail); >> + if (!(host->caps & MMC_CAP_NOT_SDIO) || !(host->caps & MMC_CAP_NOT_SD)) >> + mmc_send_if_cond(host, host->ocr_avail); >> + > > Whilst reviewing this patch it took my brain a few too many seconds to > parse that as "if the host is capable of SDIO or SD". > > >> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h >> index 0a60b02..e996967 100644 >> --- a/include/linux/mmc/host.h >> +++ b/include/linux/mmc/host.h >> @@ -150,6 +150,13 @@ struct mmc_host { >> #define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */ >> #define MMC_CAP_NONREMOVABLE (1 << 8) /* Nonremovable e.g. eMMC */ >> #define MMC_CAP_WAIT_WHILE_BUSY (1 << 9) /* Waits while card is busy */ >> +#define MMC_CAP_NOT_SDIO (1 << 10) /* Card cannot be SDIO */ >> +#define MMC_CAP_NOT_SD (1 << 11) /* Card cannot be SD */ >> +#define MMC_CAP_NOT_MMC (1 << 12) /* Card cannot be MMC */ >> + >> +#define MMC_CAP_SDIO_ONLY (MMC_CAP_NOT_SD | MMC_CAP_NOT_MMC) >> +#define MMC_CAP_SD_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_MMC) >> +#define MMC_CAP_MMC_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_SD) >> > > And by saying what capabilities a host supports, when we add new > capabilities we don't have to modify existing code to say that it > doesn't support the new capability. If the capabilities are the other way around, then all existing drivers must be changed. On the other hand, the if statement can easily be improved: #define mmc_cap_mmc(host) (!((host)->caps & MMC_CAP_NOT_MMC)) #define mmc_cap_sd(host) (!((host)->caps & MMC_CAP_NOT_SD)) #define mmc_cap_sdio(host) (!((host)->caps & MMC_CAP_NOT_SDIO)) - mmc_send_if_cond(host, host->ocr_avail); + if (mmc_cap_sdio(host) || mmc_cap_sd(host)) + mmc_send_if_cond(host, host->ocr_avail); + -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Jul 25, 2009 at 07:17:14PM +0300, Adrian Hunter wrote: > Matt Fleming wrote: >> >> And by saying what capabilities a host supports, when we add new >> capabilities we don't have to modify existing code to say that it >> doesn't support the new capability. > > If the capabilities are the other way around, then all existing drivers > must be changed. On the other hand, the if statement can easily be > improved: > > #define mmc_cap_mmc(host) (!((host)->caps & MMC_CAP_NOT_MMC)) > #define mmc_cap_sd(host) (!((host)->caps & MMC_CAP_NOT_SD)) > #define mmc_cap_sdio(host) (!((host)->caps & MMC_CAP_NOT_SDIO)) > > - mmc_send_if_cond(host, host->ocr_avail); > + if (mmc_cap_sdio(host) || mmc_cap_sd(host)) > + mmc_send_if_cond(host, host->ocr_avail); > + OK, that's a fair point, all drivers would need to be changed. However, I'm not adverse to making a one-time change to all drivers in the name of sanity. Enumerating what cards a controller doesn't support just doesn't sound correct to me. It wouldn't be a complicated change either, I'd even be happy to write the patch ;-) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Fleming wrote: > On Sat, Jul 25, 2009 at 07:17:14PM +0300, Adrian Hunter wrote: >> Matt Fleming wrote: >>> And by saying what capabilities a host supports, when we add new >>> capabilities we don't have to modify existing code to say that it >>> doesn't support the new capability. >> If the capabilities are the other way around, then all existing drivers >> must be changed. On the other hand, the if statement can easily be >> improved: >> >> #define mmc_cap_mmc(host) (!((host)->caps & MMC_CAP_NOT_MMC)) >> #define mmc_cap_sd(host) (!((host)->caps & MMC_CAP_NOT_SD)) >> #define mmc_cap_sdio(host) (!((host)->caps & MMC_CAP_NOT_SDIO)) >> >> - mmc_send_if_cond(host, host->ocr_avail); >> + if (mmc_cap_sdio(host) || mmc_cap_sd(host)) >> + mmc_send_if_cond(host, host->ocr_avail); >> + > > OK, that's a fair point, all drivers would need to be changed. However, > I'm not adverse to making a one-time change to all drivers in the name > of sanity. Enumerating what cards a controller doesn't support just > doesn't sound correct to me. > > It wouldn't be a complicated change either, I'd even be happy to write > the patch ;-) I have no objections if you write such a patch :-) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" 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 c5a7857..db43a1d 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1066,7 +1066,11 @@ void mmc_rescan(struct work_struct *work) mmc_power_up(host); mmc_go_idle(host); - mmc_send_if_cond(host, host->ocr_avail); + if (!(host->caps & MMC_CAP_NOT_SDIO) || !(host->caps & MMC_CAP_NOT_SD)) + mmc_send_if_cond(host, host->ocr_avail); + + if (host->caps & MMC_CAP_NOT_SDIO) + goto not_sdio; /* * First we search for SDIO... @@ -1078,6 +1082,10 @@ void mmc_rescan(struct work_struct *work) goto out; } +not_sdio: + if (host->caps & MMC_CAP_NOT_SD) + goto not_sd; + /* * ...then normal SD... */ @@ -1088,6 +1096,10 @@ void mmc_rescan(struct work_struct *work) goto out; } +not_sd: + if (host->caps & MMC_CAP_NOT_MMC) + goto not_mmc; + /* * ...and finally MMC. */ @@ -1098,6 +1110,8 @@ void mmc_rescan(struct work_struct *work) goto out; } +not_mmc: + mmc_release_host(host); mmc_power_off(host); diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 0a60b02..e996967 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -150,6 +150,13 @@ struct mmc_host { #define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */ #define MMC_CAP_NONREMOVABLE (1 << 8) /* Nonremovable e.g. eMMC */ #define MMC_CAP_WAIT_WHILE_BUSY (1 << 9) /* Waits while card is busy */ +#define MMC_CAP_NOT_SDIO (1 << 10) /* Card cannot be SDIO */ +#define MMC_CAP_NOT_SD (1 << 11) /* Card cannot be SD */ +#define MMC_CAP_NOT_MMC (1 << 12) /* Card cannot be MMC */ + +#define MMC_CAP_SDIO_ONLY (MMC_CAP_NOT_SD | MMC_CAP_NOT_MMC) +#define MMC_CAP_SD_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_MMC) +#define MMC_CAP_MMC_ONLY (MMC_CAP_NOT_SDIO | MMC_CAP_NOT_SD) /* host specific block data */ unsigned int max_seg_size; /* see blk_queue_max_segment_size */