From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Subject: Re: [PATCH] mmc: omap_hsmmc: fix initialization order of mmc block devices Date: Tue, 13 Oct 2015 15:59:20 +0200 Message-ID: <561D0E38.6030006@gmail.com> References: <1444714193-24816-1-git-send-email-hs@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1444714193-24816-1-git-send-email-hs@denx.de> Sender: linux-kernel-owner@vger.kernel.org To: Heiko Schocher , linux-kernel@vger.kernel.org Cc: Arnd Bergmann , linux-mmc@vger.kernel.org, Dirk Behme , Georg.Soffel@bosch-si.com, linux-omap@vger.kernel.org, Ulf Hansson List-Id: linux-mmc@vger.kernel.org On 13.10.2015 07:29, Heiko Schocher wrote: > On embedded devices, often there is a combination of > removable mmc devices (e.g. MMC/SD cards) and hard > wired ones (e.g. eMMC). Depending on the hardware > configuration, the 'mmcblkN' node might change if > the removable device is available or not at boot time. > > E.g. if the removable device is attached at boot time, > it might become mmxblk0. And the hard wired one mmcblk1. > But if the removable device isn't there at boot time, > the hard wired one will become mmcblk0. This makes it > somehow difficult to hard code the root device to the > non-removable device and boot fast. > > Signed-off-by: Heiko Schocher > --- > Dirk Behme tried to bring this in, last mail I found: > http://lists.infradead.org/pipermail/linux-arm-kernel/2012-July/111022.html > where Dirk worked in Arnds suggestion to use the > "/aliases" device node" The last attempt I remember is from last year http://www.spinics.net/lists/linux-mmc/msg26586.html http://www.spinics.net/lists/linux-mmc/msg26588.html I can't remember why this wasn't accepted, too. But maybe searching the archives will help answering that. Best regards Dirk > I adapt this to the omap_hsmmc driver. > > Is there another solution for this problem? > Or why was this patch not accepted to mainline? > > drivers/mmc/card/block.c | 6 ++++-- > drivers/mmc/host/omap_hsmmc.c | 6 ++++++ > include/linux/mmc/host.h | 3 +++ > 3 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index c742cfd..62250d8 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -2106,7 +2106,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, > struct mmc_blk_data *md; > int devidx, ret; > > - devidx = find_first_zero_bit(dev_use, max_devices); > + devidx = find_next_zero_bit(dev_use, max_devices, > + card->host->devidx); > if (devidx >= max_devices) > return ERR_PTR(-ENOSPC); > __set_bit(devidx, dev_use); > @@ -2124,7 +2125,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, > * index anymore so we keep track of a name index. > */ > if (!subname) { > - md->name_idx = find_first_zero_bit(name_use, max_devices); > + md->name_idx = find_next_zero_bit(name_use, max_devices, > + card->host->devidx); > __set_bit(md->name_idx, name_use); > } else > md->name_idx = ((struct mmc_blk_data *) > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 7fb0753..0b45b48 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -2059,6 +2059,12 @@ static int omap_hsmmc_probe(struct platform_device *pdev) > host->pbias_enabled = 0; > host->vqmmc_enabled = 0; > > + if (pdev->dev.of_node) { > + ret = of_alias_get_id(pdev->dev.of_node, "mmcblk"); > + if (ret >= 0) > + host->mmc->devidx = ret; > + } > + > ret = omap_hsmmc_gpio_init(mmc, host, pdata); > if (ret) > goto err_gpio; > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 83b81fd..4f071681 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -382,6 +382,9 @@ struct mmc_host { > int dsr_req; /* DSR value is valid */ > u32 dsr; /* optional driver stage (DSR) value */ > > + /* preferred mmc block device index (mmcblkX) */ > + unsigned int devidx; > + > unsigned long private[0] ____cacheline_aligned; > }; > >