From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH v2 2/4] mmc: mmci: move block size validation under relevant code Date: Tue, 19 Aug 2014 13:55:37 +0200 Message-ID: References: <1408446785-1399-1-git-send-email-srinivas.kandagatla@linaro.org> <1408446866-1649-1-git-send-email-srinivas.kandagatla@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1408446866-1649-1-git-send-email-srinivas.kandagatla@linaro.org> Sender: linux-mmc-owner@vger.kernel.org To: Srinivas Kandagatla Cc: linux-mmc , Linus Walleij , Chris Ball , Russell King , "linux-kernel@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" List-Id: linux-arm-msm@vger.kernel.org On 19 August 2014 13:14, Srinivas Kandagatla wrote: > This code moves a BUG_ON condition to relevant if block, this check is > not necessary for IPs which can set any arbitrary block size in a given > range. > This patch is necessary for SDIO which sets block sizes that are exactly > not power of 2. > > Original issue detected while testing WLAN ath6kl on Qualcomm APQ8064 SOC. > > Signed-off-by: Srinivas Kandagatla > --- > drivers/mmc/host/mmci.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c > index 3089fba..1c99195 100644 > --- a/drivers/mmc/host/mmci.c > +++ b/drivers/mmc/host/mmci.c > @@ -800,15 +800,16 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) > writel(timeout, base + MMCIDATATIMER); > writel(host->size, base + MMCIDATALENGTH); > > - blksz_bits = ffs(data->blksz) - 1; > - BUG_ON(1 << blksz_bits != data->blksz); I don't like this BUG_ON at all, I would prefer if we remove it. The original patch "mmc: mmci: Support any block sizes for ux500v2", did so as well. Now, if we still think removing it is fragile, let additional tests in mmci_validate_data() and return and error code from there. Kind regards Uffe > > - if (variant->blksz_datactrl16) > + if (variant->blksz_datactrl16) { > datactrl = MCI_DPSM_ENABLE | (data->blksz << 16); > - else if (variant->blksz_datactrl4) > + } else if (variant->blksz_datactrl4) { > datactrl = MCI_DPSM_ENABLE | (data->blksz << 4); > - else > + } else { > + blksz_bits = ffs(data->blksz) - 1; > + BUG_ON(1 << blksz_bits != data->blksz); > datactrl = MCI_DPSM_ENABLE | blksz_bits << 4; > + } > > if (data->flags & MMC_DATA_READ) > datactrl |= MCI_DPSM_DIRECTION; > -- > 1.9.1 >