RE: [PATCH v4 1/2] mmc: API for accessing host supported maximum segment count and size

[Amitkumar Karwar <akarwar-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>]

Hi Ulf,

> From: Amitkumar Karwar [mailto:akarwar-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org]
> Sent: Thursday, June 16, 2016 2:53 PM
> To: linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: Nishant Sarmukadam; Wei-Ning Huang; linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
> Cathy Luo; Xinming Hu; Amitkumar Karwar
> Subject: [PATCH v4 1/2] mmc: API for accessing host supported maximum
> segment count and size
> 
> From: Xinming Hu <huxm-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
> 
> 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-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Amitkumar Karwar <akarwar-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
> ---
> 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.
> v4: Removed WARN_ON() calls in newly added APIs. It's gets called in
> probe handler.
>     Caller already takes care of it(Shawn Lin).
> ---
>  drivers/mmc/core/sdio_io.c                          | 21
> +++++++++++++++++++++
>  .../wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c   |  6 +++---
>  include/linux/mmc/sdio_func.h                       |  3 +++
>  3 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> index 78cb4d5..b1ecacc 100644
> --- a/drivers/mmc/core/sdio_io.c
> +++ b/drivers/mmc/core/sdio_io.c
> @@ -720,3 +720,24 @@ 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) {
> +	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) {
> +	return func->card->host->max_segs;
> +}
> +EXPORT_SYMBOL_GPL(sdio_get_host_max_seg_count);
> +
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> index c4b89d2..ba579f4 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
> @@ -896,9 +896,9 @@ void brcmf_sdiod_sgtable_alloc(struct
> brcmf_sdio_dev *sdiodev)
>  	max_blocks = min_t(uint, host->max_blk_count, 511u);
>  	sdiodev->max_request_size = min_t(uint, host->max_req_size,
>  					  max_blocks * func->cur_blksize);
> -	sdiodev->max_segment_count = min_t(uint, host->max_segs,
> -					   SG_MAX_SINGLE_ALLOC);
> -	sdiodev->max_segment_size = host->max_seg_size;
> +	sdiodev->max_segment_count = min_t(uint, SG_MAX_SINGLE_ALLOC,
> +					   sdio_get_host_max_seg_count(func));
> +	sdiodev->max_segment_size = sdio_get_host_max_seg_size(func);
> 
>  	if (!sdiodev->sg_support)
>  		return;
> diff --git a/include/linux/mmc/sdio_func.h
> b/include/linux/mmc/sdio_func.h index aab032a..b2b91df 100644
> --- a/include/linux/mmc/sdio_func.h
> +++ b/include/linux/mmc/sdio_func.h
> @@ -159,4 +159,7 @@ extern void sdio_f0_writeb(struct sdio_func *func,
> unsigned char b,  extern mmc_pm_flag_t sdio_get_host_pm_caps(struct
> sdio_func *func);  extern int sdio_set_host_pm_flags(struct sdio_func
> *func, mmc_pm_flag_t flags);
> 
> +unsigned short sdio_get_host_max_seg_count(struct sdio_func *func);
> +unsigned int sdio_get_host_max_seg_size(struct sdio_func *func);
> +
>  #endif /* LINUX_MMC_SDIO_FUNC_H */

This has been pending for a while.
Any further review comments on this v4 patch series?

Regards,
Amitkumar Karwar