Sorry for late this.. On 10/18/2017 12:52 AM, Liming Sun wrote: >>> Hrm.... it's so unlucky that your patchset comes a little late. As your >>> patch 8 and 9 said, you need them to fix problem for multi-card support, so >>> definitely there was no such use case, and even the code was buggy to >>> support it right? That makes the code hard to read and maintain, so we >>> decide to remove it. > > Thanks for the feedback. Yes, earlier the multi-card support was buggy > indeed. We spent some time to debug it and got it working. > >>> Havn'e check the databook for details yet, but I think it's ok to >>> re-introduce multi-slot support if a real user benefits from it. But you >>> need a new patch to silent the log "num-slots property not found, assuming >>> 1 slot is available" as we removed all the num-slots from DT at that time. > > The " num-slots property not found..." log message has already been removed > by 8a629d26f back in 2016. Looks like we're good on this one. In dw_mci_probe > (), it has code to check pdata->num_slots. If 0, the host->num_slots will be > set to 1. So the logic of setting default num_slots seems already there. But > correct me if I am wrong. > > Thanks, > Liming > > -----Original Message----- > From: Shawn Lin [mailto:[email protected]] > Sent: Monday, October 16, 2017 9:36 PM > To: Liming Sun <[email protected]>; Jaehoon Chung <[email protected]> > Cc: Ulf Hansson <[email protected]>; Rob Herring <[email protected]>; > Mark Rutland <[email protected]>; Kukjin Kim <[email protected]>; Krzysztof > Kozlowski <[email protected]>; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected] > Subject: Re: [PATCH 0/9] Enable dw-mmc multi-card support > > > On 2017/10/7 3:21, Liming Sun wrote: >> This series of commits enables the multi-card support for the dw-mmc >> controller. It includes two parts as below. >> >> The first part (patches 1-7) reverts the series of recent commits that >> removed the multi-card support with comments saying there was no such >> use case in the real world. Actually this feature is being used in >> Mellanox Bluefield SoC and has been requested by customers. > > Hrm.... it's so unlucky that your patchset comes a little late. As your patch > 8 and 9 said, you need them to fix problem for multi-card support, so > definitely there was no such use case, and even the code was buggy to support > it right? That makes the code hard to read and maintain, so we decide to > remove it.
Hmm.. Well, if i missed your reply for my removing patch, it's my fault..but i didn't see any reply.. At that time, we didn't see any usage and also now... Are there any patches for using multi slot? e,g) device-tree file or your own driver If there are big benefits to revert them, i don't want to back them..during almost 6 years, never use it.. > >> >> The second part (patches 8-9) fixes the DesignWare multi-card support >> according to the dw-mmc databook (synnopsys: DesignWare Cores Mobile >> Storage Host Databook, 2.70a). It has changes to set the card number >> into the CMD register to multiplex requests to different cards when >> working in SD_MMC_CEATA mode, set the CTYPE / CLKENA / CDTHRCTL >> registers properly according to the spec, and parse the per-card >> configuration to match the Linux Documentation >> (bindings/mmc/synopsys-dw-mshc.txt). the second part seems that it's only support since v2.70a..? > > Havn'e check the databook for details yet, but I think it's ok to > re-introduce multi-slot support if a real user benefits from it. But you need > a new patch to silent the log "num-slots property not found, assuming 1 slot > is available" as we removed all the num-slots from DT at that time. > > >> >> Liming Sun (9): >> Revert "Documentation: dw-mshc: deprecate num-slots" >> Revert "mmc: dw_mmc: remove the unnecessary slot variable" >> Revert "mmc: dw_mmc: use the 'slot' instead of 'cur_slot'" >> Revert "mmc: dw_mmc: remove the 'id' arguments about functions >> relevant to slot" >> Revert "mmc: dw_mmc: change the array of slots" >> Revert "mmc: dw_mmc: remove the loop about finding slots" >> Revert "mmc: dw_mmc: deprecated the "num-slots" property" >> mmc: dw_mmc: Support two SD_MMC_CE-ATA cards >> mmc: dw_mmc: Parse slot-specific configuration >> >> .../devicetree/bindings/mmc/synopsys-dw-mshc.txt | 16 +- >> drivers/mmc/host/dw_mmc-exynos.c | 4 +- >> drivers/mmc/host/dw_mmc.c | 277 >> ++++++++++++++++----- >> drivers/mmc/host/dw_mmc.h | 17 +- >> 4 files changed, 236 insertions(+), 78 deletions(-) >> > > > >
