From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH 3/3] MMC/SD: add callback function to detect card Date: Tue, 31 Aug 2010 22:23:23 +0300 Message-ID: <4C7D56AB.1060307@nokia.com> References: <1259913309-27146-1-git-send-email-r66093@freescale.com> <20100827190513.GC20407@void.printf.net> <20100831191040.GB7847@console-pimps.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([192.100.122.233]:40525 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754999Ab0HaTXi (ORCPT ); Tue, 31 Aug 2010 15:23:38 -0400 In-Reply-To: <20100831191040.GB7847@console-pimps.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Matt Fleming Cc: Chris Ball , "r66093@freescale.com" , "linux-mmc@vger.kernel.org" , Jerry Huang Matt Fleming wrote: > On Fri, Aug 27, 2010 at 08:05:13PM +0100, Chris Ball wrote: >> Hi, >> >> On Fri, Dec 04, 2009 at 03:55:09PM +0800, r66093@freescale.com wrote: >>> From: Jerry Huang >>> >>> Add callback function to check if the card has been removed. >>> >>> in order to check if the card has been removed, the function mmc_send_status will send commad CMD13 to card and ask the card to send its status register to driver, which will generate interrupt repeatly and make the system bad. >>> Therefore, get_cd callback is used to detect the card if the driver has. >>> >>> Signed-off-by: Jerry Huang >>> --- >>> drivers/mmc/core/mmc.c | 5 ++++- >>> drivers/mmc/core/sd.c | 5 ++++- >>> 2 files changed, 8 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c >>> index 06084db..c5c676d 100644 >>> --- a/drivers/mmc/core/mmc.c >>> +++ b/drivers/mmc/core/mmc.c >>> @@ -494,7 +494,10 @@ static void mmc_detect(struct mmc_host *host) >>> /* >>> * Just check if our card has been removed. >>> */ >>> - err = mmc_send_status(host->card, NULL); >>> + if (host->ops->get_cd) >>> + err = !host->ops->get_cd(host); >>> + else >>> + err = mmc_send_status(host->card, NULL); >>> >>> mmc_release_host(host); >>> >>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c >>> index cd81c39..3cf1f38 100644 >>> --- a/drivers/mmc/core/sd.c >>> +++ b/drivers/mmc/core/sd.c >>> @@ -548,7 +548,10 @@ static void mmc_sd_detect(struct mmc_host *host) >>> /* >>> * Just check if our card has been removed. >>> */ >>> - err = mmc_send_status(host->card, NULL); >>> + if (host->ops->get_cd) >>> + err = !host->ops->get_cd(host); >>> + else >>> + err = mmc_send_status(host->card, NULL); >>> >>> mmc_release_host(host); >>> >>> -- >>> 1.6.4 >> This patchset wasn't replied to -- any comments on it from the list? > > I think this change makes sense, although it needs to be a bit smarter > with error handling because the get_cd() functions can return -ENOSYS if > they are not implemented (but the function pointer is still valid). > > int err = 0; > > if (host->ops->get_cd) { > err = host->ops->get_cd(host); > if (err >= 0) > err = !err; > } > > if (!host->ops->get_cd || err < 0) > err = mmc_send_status(host->card, NULL); > > Thoughts? I am not sure it won't cause problems. If you change the card then card detect will return true because there is a card but send status will fail because the card is not initialised. So the two do not seem equivalent. > -- > 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 >