Hi Shawn, > From: Shawn Lin [mailto:shawn.lin@xxxxxxxxxxxxxx] > Sent: Wednesday, June 08, 2016 7:31 AM > To: Amitkumar Karwar; linux-wireless@xxxxxxxxxxxxxxx > Cc: Nishant Sarmukadam; Wei-Ning Huang; linux-mmc@xxxxxxxxxxxxxxx; Cathy > Luo; Xinming Hu; shawn.lin@xxxxxxxxxxxxxx > Subject: Re: [PATCH v3 1/2] mmc: API for accessing host supported > maximum segment count and size > > Hi > > On 2016-6-6 19:53, Amitkumar Karwar wrote: > > From: Xinming Hu <huxm@xxxxxxxxxxx> > > > > sdio device drivers need be able to get the host supported max_segs > > and max_seg_size, so that they know the buffer size to allocate while > > utilizing the scatter/gather DMA buffer list. > > > > This patch provides API for this purpose. > > > > Signed-off-by: Xinming Hu <huxm@xxxxxxxxxxx> > > Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx> > > --- > > v2: v2 was submitted with minor improvement like replacing BUG_ON() > > with WARN_ON() > > v3: Addressed below review comments from Ulf Hansson > > a) In v3, patch has been split into two separate patches. > > b) Patch 1/2 introduces an API to fetch max_seg_size and max_segs > > c) Replaced WARN_ON() with proper error code when sg_ptr->length > is invalid > > d) Instead of duplicating the code in mmc_io_rw_extended(), extra > bool parameter > > has been added to this function and used it in new APIs for > SG. > > --- > > drivers/mmc/core/sdio_io.c | 27 > ++++++++++++++++++++++ > > .../wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 6 ++--- > > include/linux/mmc/sdio_func.h | 3 +++ > > 3 files changed, 33 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c > > index 78cb4d5..a546c89 100644 > > --- a/drivers/mmc/core/sdio_io.c > > +++ b/drivers/mmc/core/sdio_io.c > > @@ -720,3 +720,30 @@ int sdio_set_host_pm_flags(struct sdio_func > *func, mmc_pm_flag_t flags) > > return 0; > > } > > EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags); > > + > > +/** > > + * sdio_get_host_max_seg_size - get host maximum segment size > > + * @func: SDIO function attached to host > > + */ > > +unsigned int sdio_get_host_max_seg_size(struct sdio_func *func) { > > + WARN_ON(!func); > > + WARN_ON(!func->card); > > + > > + return func->card->host->max_seg_size; } > > +EXPORT_SYMBOL_GPL(sdio_get_host_max_seg_size); > > + > > +/** > > + * sdio_get_host_max_seg_count - get host maximum segment count > > + * @func: SDIO function attached to host > > + */ > > +unsigned short sdio_get_host_max_seg_count(struct sdio_func *func) { > > + WARN_ON(!func); > > + WARN_ON(!func->card); > > + > > I believe these two WARN_ON may be called too late because ... > > drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > > void brcmf_sdiod_sgtable_alloc(struct brcmf_sdio_dev *sdiodev) > > func = sdiodev->func[2]; > host = func->card->host; > > you have unconditionally thought it should be ready. > Yes. The WARN_ONs in this patch are redundant. We will remove them and submit updated version. Below is the function call flow. brcmf_sdio_probe() -> brcmf_sdio_probe_attach() -> brcmf_sdiod_sgtable_alloc() Looks like is sdiodev->func[2] is ready in brcmf_sdio_probe() itself. It contains below line. bus->blocksize = bus->sdiodev->func[2]->cur_blksize; Regards, Amitkumar -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
