From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [RFC PATCH 05/11] dma: amba-pl08x: Add support for different maximum transfer size Date: Mon, 17 Jun 2013 20:27:20 +0200 Message-ID: <5634002.KI4n5O8hcE@flatron> References: <1371416058-22047-1-git-send-email-tomasz.figa@gmail.com> <1371416058-22047-6-git-send-email-tomasz.figa@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Linus Walleij Cc: "alsa-devel@alsa-project.org" , Heiko =?ISO-8859-1?Q?St=FCbner?= , Padmavathi Venna , Takashi Iwai , Alessandro Rubini , "linux-kernel@vger.kernel.org" , Giancarlo Asnaghi , Kukjin Kim , Russell King - ARM Linux , Vinod Koul , Thomas Abraham , Grant Likely , Arnd Bergmann , linux-samsung-soc , Sylwester Nawrocki , Jaroslav Kysela , "linux-arm-kernel@lists.infradead.org" , Sangbeom Kim , Liam Girdwood , linux-spi@vger.kernel. List-Id: alsa-devel@alsa-project.org On Monday 17 of June 2013 15:42:15 Linus Walleij wrote: > On Sun, Jun 16, 2013 at 10:54 PM, Tomasz Figa wrote: > > PL080S has separate register to store transfer size in, allowing > > single > > transfer to be much larger than in standard PL080. > > > > This patch makes the amba-pl08x driver aware of this and removes > > writing transfer size to reserved bits of CH_CONTROL register on > > PL080S, which was not a problem witn transfer sizes fitting the > > original bitfield of PL080, but now would overwrite other fields. > > > > Signed-off-by: Tomasz Figa > > Very straight-forward. > Reviewed-by: Linus Walleij Thanks. Actually today I found another way of doing this, which wouldn't require checking PL08X_IS_PL080S flag at all. Simply masking the transfer size in pl08x_cctl_bits() with mask of the original bitfield would be enough I think, as writes to those bits seem to be ignored on PL080S. Best regards, Tomasz From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomasz.figa@gmail.com (Tomasz Figa) Date: Mon, 17 Jun 2013 20:27:20 +0200 Subject: [RFC PATCH 05/11] dma: amba-pl08x: Add support for different maximum transfer size In-Reply-To: References: <1371416058-22047-1-git-send-email-tomasz.figa@gmail.com> <1371416058-22047-6-git-send-email-tomasz.figa@gmail.com> Message-ID: <5634002.KI4n5O8hcE@flatron> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 17 of June 2013 15:42:15 Linus Walleij wrote: > On Sun, Jun 16, 2013 at 10:54 PM, Tomasz Figa wrote: > > PL080S has separate register to store transfer size in, allowing > > single > > transfer to be much larger than in standard PL080. > > > > This patch makes the amba-pl08x driver aware of this and removes > > writing transfer size to reserved bits of CH_CONTROL register on > > PL080S, which was not a problem witn transfer sizes fitting the > > original bitfield of PL080, but now would overwrite other fields. > > > > Signed-off-by: Tomasz Figa > > Very straight-forward. > Reviewed-by: Linus Walleij Thanks. Actually today I found another way of doing this, which wouldn't require checking PL08X_IS_PL080S flag at all. Simply masking the transfer size in pl08x_cctl_bits() with mask of the original bitfield would be enough I think, as writes to those bits seem to be ignored on PL080S. Best regards, Tomasz