On Thu, 23 Jun 2011 11:09:34 +0800 Dirk Brandewie <[email protected]> wrote:
> On 06/22/2011 07:45 PM, Feng Tang wrote: > > On Thu, 23 Jun 2011 10:00:11 +0800 > > "[email protected]"<[email protected]> wrote: > > > >> From: Dirk Brandewie<[email protected]> > >> > >> Fix the condition based on whether the current transfer has a tx/rx > >> buffer. > >> > >> Signed-off-by: Dirk Brandewie<[email protected]> > >> --- > >> drivers/spi/spi-dw.c | 6 +++--- > >> 1 files changed, 3 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c > >> index cc38aa0..35b952b 100644 > >> --- a/drivers/spi/spi-dw.c > >> +++ b/drivers/spi/spi-dw.c > >> @@ -193,8 +193,8 @@ static void spi_dw_writer(struct spi_dw *dws) > >> u16 txw = 0; > >> > >> while (max--) { > >> - /* Set the tx word if the transfer's original "tx" > >> is not null */ > >> - if (dws->tx_end - dws->len) { > >> + /* Set the tx word if the transfer's "tx" is not > >> null */ > >> + if (dws->tx) { > > > > No, in current mainstream code, the dws->tx is changing, see code: > > dws->tx += dws->n_bytes; > > so we have to use if (dws->tx_end - dws->len) for now, maybe > > we can use some bit to indicate whether the original tx is null > > If dws->tx is non-null then it points to a valid buffer, it is > unconditionally set with dws->tx = (void *)transfer->tx_buf when the > transfer is setup. if the original transfer->tx_buf is non-null then > this change works. dws->tx is changing as I said, non-null doesn't mean the value is valid, when the original tx is null, we don't access it at all, it's just a indicator of whether the dws->len of zeor has been filled to FIFO. This logic may looks confusing, but it's correct after years of test. > > > > >> if (dws->n_bytes == 1) > >> txw = *(u8 *)(dws->tx); > >> else > >> @@ -213,7 +213,7 @@ static void spi_dw_reader(struct spi_dw *dws) > >> while (max--) { > >> rxw = dw_readw(dws, dr); > >> /* Care rx only if the transfer's original "rx" > >> is not null */ > >> - if (dws->rx_end - dws->len) { > >> + if (dws->rx) { > >> if (dws->n_bytes == 1) > >> *(u8 *)(dws->rx) = rxw; > >> else > ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
