On Thu, Mar 01, 2018 at 06:27:01PM +0800, Sean Wang wrote: > On Thu, 2018-03-01 at 13:53 +0530, Vinod Koul wrote: > > On Sun, Feb 18, 2018 at 03:08:30AM +0800, sean.wang@xxxxxxxxxxxx wrote: > > > > > @@ -0,0 +1,1054 @@ > > > +// SPDX-License-Identifier: GPL-2.0 > > // Copyright ... > > > > The copyright line needs to follow SPDX tag line > > > > okay, I will make it reorder and be something like that > > // SPDX-License-Identifier: GPL-2.0 > /* > * Copyright (c) 2017-2018 MediaTek Inc. > * Author: Sean Wang <sean.wang@xxxxxxxxxxxx> > * > * Driver for MediaTek High-Speed DMA Controller > * > */ It needs to be: // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017-2018 MediaTek Inc. /* * whatever else you want */ The first two lines are in C99 style comment and need to have SPDX tag and Copyright info > the point is I learned from other subsystem makes the driver name be > same with the module name with KBUILD_MODNAME. > > If you really don't like it, I can just change it into > > #define MTK_DMA_DEV "mtk-hsdma" It is used only once, why not use KBUILD_MODNAME directly? > > > > + > > > +#define MTK_HSDMA_USEC_POLL 20 > > > +#define MTK_HSDMA_TIMEOUT_POLL 200000 > > > +#define MTK_HSDMA_DMA_BUSWIDTHS BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) > > > > Undefined buswidth?? ?? > > > +/** > > > + * struct mtk_hsdma_pdesc - This is the struct holding info describing physical > > > + * descriptor (PD) and its placement must be kept at > > > + * 4-bytes alignment in little endian order. > > > + * @desc[1-4]: The control pad used to indicate hardware how to > > > > pls align to 80char or lesser > > > > weird, it seems the line is already with 80 char and pass the > checkpatch.pl. or do I misunderstand something ? Okay please check. With text it helps to wrap before that > > > + /* > > > + * Updating into hardware the pointer of TX ring lets HSDMA to take > > > + * action for those pending PDs. > > > + */ > > > + mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, ring->cur_tptr); > > > + > > > + spin_unlock_irqrestore(&hsdma->lock, flags); > > > + > > > + return !hvd->len ? 0 : -ENOSPC; > > > > you already wrote and started txn, so why this? > > > > it's possible just partial virtual descriptor fits into hardware and > then return -ENOSPC. And it will start it to complete the remaining part > as soon as possible when some rooms is being freed. Either ways you have issued the descriptor, so you succeed right? > > shouldn't we check if next is in range, we can crash if we get bad value > > from hardware.. > > okay, there are checks for next with ddone bit check and null check in > the corresponding descriptor as the following. what if you get bad next value > > > > + rxd = &pc->ring.rxd[next]; resulting in bad ref here -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
